Purigen98 Evidence and Science Support Manual

PURIGEN98 Authorized Dealer EVIDENCE MANUAL

PurigeN98 Evidence and Science Support Manual

*** NOTICE *** THIS EVIDENCE MANUAL HAS BEEN ASSEMBLED TO PROVIDE PURIGEN98 AUTHORIZED DEALERS WITH INDEPENDENT RESEARCH DATA AND ANALISYS TO SUPPORT CLAIMS AND BENEFITS MADE WITH THE PURIGEN98 TIRE INFLATION PROGRAM. THIS MANUAL MAY BE USED BY AUTHORIZED PURIGEN98 DEALERS ONLY.

Dear PurigeN98 Dealer:

This manual contains independent and up to date information, research, statements regarding the benefits of nitrogen tire inflation. The manual provide information on tire inflation statistics, safety records, environmental benefits, Fuel efficiency research and tire wear benefits. Please incorporate this manual with your other reference materials. PurigeN98 benefits are supported by many different institutions, companies and organizations.

All quotes and statements are referenced with source name and corresponding page number of the complete article contained in this manual.

Please feel free to call our corporate offices for additional copies or additional questions. N2Revolution, Inc. 523 Sawgrass Corporate Parkway Sunrise, Florida 33325 Phone (954) 838-7545 Fax (954) 337-4614 [email protected] www.purigen98.com

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NITROGEN INFLATION BENEFITS

Page 14 Bridgestone Ask the Doctor

Page 15 Bridgestone Ask the Doctor

Ford Paper Page 17

Ford Paper Page 24

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Air Products Paper Page 34

Air Products Paper Page 35

Air Products Paper Page 36

Air Products Paper Page 37

Italian Thesis Page 54

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Italian Thesis Page 56

Air Liquide Permeation Speed Graph. Page 59

TRIB Page 61

TRIB Page 62

AIDA Page 68

RMA Brochure Page 127

GAO Report Page 130

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General Motors Bulletin Page 151

Ford Motor Service Bulletin Page 148

Daimler Chrysler Email page 154

Paper presented at ITEC page 162

FUEL SAVINGS

TOYO Fuel Efficiency Paper Page 70

Carnegie Mellon Page 72

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Carnegie Mellon Page 73

Michigan Dept. of Transportation Page 74

Dunlop Page 83

Fueleconomy.gov Page 84

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Get Nitrogen Institute Page 85

EPA Smartway Page 94

TIRE WEAR

Bridgestone Page 75

Bridgestone Page 76

Bridgestone Survey Page 78

Dunlop Tires Page 82

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GoodYear Manual Page 87

US DOT Page 88

RMA Canada Page 91

RMA Canada Page 92

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EPA Smartway Page 94

Autosmart Page 100

SAFETY

US DOT Page 88

TIA Page 95

TMC Page 112

Michelin Statement Page 126

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GAO Report Page 130

OTHER RESEARCH

NCSA Page 125

-CONFIDENTIAL – This document may be used by Authorized PurigeN98 Dealers Only Reprinted from Real Answers SHOULD YOU STOP PUTTING AIR IN YOUR TIRES? Volume 8, Issue 3

www.trucktires.com 1-800-543-7522

Should you stop putting air in your tires

As much as we preach inflation pressure maintenance, that might seem like a ludicrous question. What’s behind it, though, is the issue of whether or not air is the best thing to use for inflating tires.

Lately, there’s been more and more interest is using other gases, like nitrogen. Unfortunately, there’s also a certain amount of bogus information out there regarding nitrogen as well. We’ll try to provide some “real answers” regarding nitrogen’s potential.

Is nitrogen inflation new? How does that happen? It’s been used on giant off-highway Air migrates through rubber. Truck tires can lose 2 psi tires, on aircraft tires, and on per month as a result of air passing through their side- racing tires for many years. walls – like a balloon that shrivels up, but much slower. Off-highway tires, aircraft tires and racecar tires That’s why regular inflation pressure checks are have used nitrogen inflation for quite some time. a must. Even if there’s nothing “wrong,” you can still be losing pressure. And, when oxygen passes through rubber, it can Why did they switch? come into contact with steel cords, causing them Air is about one-fifth oxygen, to rust too. and oxygen, especially at high temperatures and Between aging rubber and corroding steel cords, pressures, is a very reactive element. oxygen reduces retreadability. When oxygen reacts with things, the process is called oxidation. When oxidation is extremely rapid, How does nitrogen help? the process is called “burning.” While both nitrogen and oxygen can That’s one reason nitrogen is used in off-highway permeate rubber, nitrogen does it much and aircraft tires. These tires run so hot they can more slowly. It might take six months actually catch on fire. Because air can to lose 2 psi with nitrogen, compared Nitrogen doesn’t support combustion, so migrate through sidewalls, to just a month with air. nitrogen-filled tires don’t add fuel to the flames. truck tires can lose And, nitrogen is far less reactive. And, nitrogen helps prevent slower forms of up to 2 psi per month, It doesn’t cause rust and corrosion on oxidation too. even when valves and steel or aluminum, and it doesn’t beads seal properly and there are no punctures. degrade rubber. AIR: Wheel surfaces stay smooth and 78.1% Nitrogen clean, rubber remains supple and resilient. Inflation 20.9% Oxygen losses are minimized – and retreadability is enhanced. 1% Other Gases Are there other benefits to nitrogen inflation? What are those? The air around us is full of water vapor. It’s called Oxygen corrodes aluminum “humidity.” Compressing air concentrates the water in it. and steel wheels. And, oxygen Draining water from your air lines every day helps, reacts with rubber, in a sense, but unless you have a really efficient air dryer, chances “corroding” it too. are there’s lots of water in your compressed air. Rust and dust from wheels When you compress air, it takes up can clog valve stems, causing them to leak. much less volume, but the percentage 120 of water by volume is greatly increased. And, rough surfaces on wheel flanges and tire beads psi 0 may not seal properly, causing additional leaks. psi Oxygen also ages the innerliner, that thin layer of rubber inside the tire whose function is keeping air away from the carcass. As the innerliner ages, more and more air molecules can pass What’s the harm in that? through it, causing more pressure losses. Water vapor in compressed air acts as a catalyst, accelerating rust and corrosion. Water vapor also absorbs and holds Small bits of corrosion from wheels can prevent valves heat. And, when it changes from liquid to from seating properly, leading to loss of air pressure. vapor, water expands tremendously in volume. So, tires inflated with wet air tend to run WATER + HEAT hotter and fluctuate in pressure more. That’s why racing tires, where fractions of a psi can =VAPOR radically change handling, are inflated with dry nitrogen. 3

FOR USE BY PURGEN98 DEALERS ONLY Page 14 of 168 Benefits of Nitrogen Inflation • Less inflation pressure loss • Less inflation pressure Is nitrogen inflation cost-effective? fluctuation with heat That’s going to depend on your situation. If your trailers go out and don’t come back for six months or more, • Reduced wheel corrosion being able to keep consistent inflation pressures may • Longer tread life greatly lengthen tread life. Some tests have shown increases of up to 26 percent. • Improved retreadability Less rubber aging and tire cord rust could also yield a higher proportion of retreadable casings – Where would we get nitrogen? and casings that can survive more retread cycles. That cuts cost per mile too. Some people use high pressure cylinders or big There’s nothing you can do that is better containers of liquid nitrogen as their source, but for your tires than maintaining the right several companies now offer machines that inflation pressure – all the time. Nitrogen could separate nitrogen from air. help you do that. We’ll keep you posted on develop- These machines can produce ments in this area. nitrogen that’s 95 percent or more pure, taking it from the inexhaustible supply in the air around us.

Do we have to do something special to fill our tires? Parts N2 Not really. If you take a + Parts other gases truck tire that’s just been add Nitrogen 95 + 5 mounted, and inflate it add Nitrogen 95 + 5 While dry nitrogen with 95 percent nitro- add Nitrogen 95 + 5 gen, you’ll end up with is available from add Nitrogen 95 + 5 welding supply shops, a concentration of about there are also 93 percent nitrogen in add Nitrogen 95 + 5 machines that will the tire. That’s good add Nitrogen 95 + 5 extract nitrogen from air. enough to do the job. add Nitrogen 95 + 5 to “Empty” tire 80 + 20 Why wouldn’t it be 95 percent? Because the tire was full of air. So there was some 745 + 55 Total: = 800 parts oxygen in it before you added the nitrogen. 745 parts nitrogen What do we do when we’re out on the road? ÷ 800 parts all gases Chances are, as it becomes more popular, you’ll find = 93% nitrogen nitrogen inflation equipment at truckstops. But in the meantime, consider this: With nitrogen inflation, you won’t need to “top off” your tires nearly as often – or as much. When you take And, if you do need to add pressure, the little bit of an “empty” tire and air that you might put in will have very little effect. add enough 95 percent If you have nitrogen inflation capability at “home,” pure nitrogen to bring its pressure up to about 105 psi, when trucks come in, you can let the air out of their the nitrogen concentration tires and re-inflate them with near-pure nitrogen. inside ends up being That will bring the concentration of nitrogen inside about 93 percent. your tires back to optimum levels.

Effects of Nitrogen Inflation on Tire Aging and Performance

By John M. Baldwin David R. Bauer Kevin R. Ellwood

Ford Motor Company Dearborn, MI

Presented at a meeting of the

Rubber Division, American Chemical Society

Grand Rapids, MI

May 17-19, 2004

John Baldwin Page 1 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 16 of 168 ABSTRACT

There has been a substantial amount of interest in N2 inflation of tires over the years. N2 tire inflation is used in the aerospace and racing industries and is beginning to make inroads into the long haul trucking industry. Some of the main benefits of using N2 as an inflation medium are: higher air pressure retention due to lower permeability than O2 through IIR, NR, and SBR compounds (which leads to improved gas mileage); linear volume expansion with temperature because of nitrogen's inherently low water absorption characteristics; and the expected improvement in structural durability due to a significant reduction in rubber oxidation (oxidation caused by air from the cavity being forced into the tire carcass). With the advent and commercialization of polymer membrane separation techniques, N2 generation has become much more affordable and easier to maintain than in the past. This paper will investigate the effect N2 inflation has on the oven aging performance of passenger tires. Results from field aging studies, along with oven aging studies using air and a 50/50 mixture of N2/O2 as inflation media, show significant changes in the tire rubber properties with time. When N2 is used as the inflation media, the change in rubber properties is significantly slowed down or even halted.

John Baldwin Page 2 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 17 of 168 INTRODUCTION

N2 tire inflation is common to several industries. The aerospace industry uses nitrogen because of its consistent inflation pressure retention and reduction of oxidation in the rubber compounds. Auto and motorcycle racing use nitrogen because it is inherently dry compared to compressed air. Depending on the humidity of the inflation air, tire pressure can change dramatically (and non-linearly) during the heat build caused by racing. Nitrogen performs predictably as an ideal gas because it does not readily absorb or carry water. Large tires used on off-road vehicles in the mining industry, for example, use nitrogen to prevent auto-ignition of the tires due to the high temperatures and thick treads. Adoption of nitrogen tire inflation into passenger and truck tires has been much slower. Some reasons for the slower adoption rate of nitrogen inflation into mainstream applications are: 1) accessibility to nitrogen inflation systems, 2) Cost of nitrogen inflation systems, both to the provider and the user, 3) Dearth of information as to the benefits of nitrogen inflation for either the fleet owner or average consumer. One benefit of using N2 is claimed to be higher air pressure retention because of the lower permeability of N2 than O2 through IIR, NR, and SBR compounds. While this is true in controlled laboratory tests of pressure retention in tires, the benefit to the real world consumer could be somewhat less. Pressure loss due to leakage around the rim flange seal of the tire to the rim and also the valve seal to the wheel (plus pressure loss through the valve itself) could account for some of the air loss experienced by the typical consumer, for example. The characteristic linear volume expansion with temperature because of nitrogen's inherently low water absorption characteristics is no benefit to the average driver because the handling requirements for daily commuting are nowhere near as demanding as for racing; the improvement would be negligible and imperceptible. The expected improvement in structural durability due to a significant reduction in rubber oxidation; however, could be a tremendous benefit to both the fleet owner and consumer. It is believed that rubber oxidation in the interior of a tire is caused by air from the cavity being forced into the tire carcass1. The National Highway Traffic Safety Administration (NHTSA) recently completed a study into the physical and chemical properties of field aged tires, including the mechanism of aging2. The NHTSA study included 'cut tire' analysis of approximately 150 tires retrieved from the field manufactured by Bridgestone/Firestone™, Goodyear™ and Michelin™. To quote from the study:

"The general pattern of change indicates that cross-link density evolution due to aerobic and thermal aging is the dominant aging factor."

The tires that were the focus of the NHTSA study were found to be defective in part because the physical properties of the rubber in the steel belt area had deteriorated due to oxidative aging. Studies conducted by this laboratory confirm the NHTSA findings3. Further work has demonstrated that accelerated oxidative aging of tires can be accomplished by use of an oven and the mechanism of aging is identical to tires obtained from the field4, 5. If the use of nitrogen as the inflation media can slow down or

John Baldwin Page 3 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 18 of 168 retard the oxidative degradation of tire rubber, then the durability of the tire should be improved. One mechanism for how tire durability could be improved is by reducing the oxidative aging of the wedge rubber. The wedge rubber in a steel belted radial tire is added to help prevent belt edge separations from occurring. It is for this reason that the wedge rubber is one of the most important tire components; the wedge rubber helps determine the durability of a tire. As a tire goes through repeated stress cycling during its lifetime, the strains are the greatest at the belt edge. When the wedge rubber aerobically ages, the material begins to stress harden. This stress hardening lowers the elongation at break and may lower its resistance to crack growth during the stress cycles. This is important because tread and belt delaminations start with cracks growing from the wedge inward between the steel belts. Nitrogen inflation could prevent the wedge from stress hardening, thus improving the crack growth resistance, which in turn would improve tire durability. Earlier work done on tube-type bias ply tires and roadwheel tested steel-belted radials has shown improvements in durability compared to air inflated tires6, 7. The research presented in this paper will concentrate on the effect nitrogen tire inflation has on the change in rubber properties around the steel belt of the tire. Tires inflated with 96% and 99.9% nitrogen were oven aged at 60°C for 3 to 12 weeks. For comparison, tires inflated with either air or a 50/50 mixture of N2/O2 were oven aged alongside the nitrogen inflated tires. After aging, tires were cut and a number of tests were performed. These included the measurement of peel force between the first and second steel belt, which is a measure of the tearing energy of skim rubber. Tensile and elongation properties were also obtained from samples of the wedge rubber located between the steel belts in the shoulder.

John Baldwin Page 4 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 19 of 168

EXPERIMENTAL

MATERIALS

One tire type was used in the study, a Goodyear Wrangler AP® LT245/75R16 (DOT Code: MD11APWV4003). Tires were mounted and inflated to the maximum pressure listed on the sidewall prior to oven aging: 450 kPa (65 psi). In the case of tires inflated with the 50/50 blend of N2/O2, the atmospheric air present was not purged; the blend was added on top of it yielding a tire cavity concentration of approximately 44% O2. For tires inflated to 96% nitrogen, 99.9% pure nitrogen was added on top of the atmospheric air present in the tire cavity, thus yielding the 96% concentration. The tires yielding 99.9% pure nitrogen cavities were inflated and purged 10 times each with 99.9% nitrogen. Tires were aged in the same ovens for 3, 6, 9, and 12 weeks @ 60°C. New tires were analyzed unaged and used as the baseline condition. The ovens were calibrated per ASTM E 145 with an A2LA approved, modified, method for temperature uniformity, consistency, air flow exchanges and airflow velocity.

PHYSICAL PROPERTIES

Tensile and Elongation. - Samples of the belt wedge rubber (Figure 1), located between belts 1 and 2 were removed from both shoulders of unaged and aged tires and buffed to a uniform thickness of 0.5 to 1.0 mm. Care was taken so that no significant heat was introduced to the samples by the buffing. Specimens were die-cut using an ASTM D 638 Type V dumbbell die and tested per ASTM D 412. Results obtained included stresses @ 25%, 50%, 100% strain, and each 100% strain thereafter, ultimate elongation and tensile strength. Samples were tested at 20" per minute (50.8 cm/minute). Peel Strength. - Samples were prepared by cutting 2.5" (63.5 mm) wide radial sections, bead to bead. The sample was then sectioned into two 1.25" (31.75 mm) radial strips, which were each cut circumferentially at the centerline of the tread, resulting in four test specimens (2-SS and 2-OSS). Each sample was cut with a razor knife for a length of 1" (25.4 mm), from the skim end of the test strip, midway between the belts; to facilitate gripping the ends in the T-2000 Stress/Strain Tester jaws. The 1 sides of each specimen were scored midway between the belts, to a depth of /8" (3.175 mm) radially from the end of the gripping surface to the end of belt #2 in the shoulder area, providing a 1" wide peel section. The peel test was performed at 2" per minute (50.8 mm) at 24°C. Reconstruction of Skim and Wedge Rubber Chemical Formulation. - An attempt was made to reconstruct the formulation. As the reader is undoubtedly aware, chemical reconstruction of a thermoset rubber is difficult and the precise formulation is known only to the compounder. Nevertheless, it is important to understand, at least generally, the chemical make-up of the compound one is studying. Table 1 contains the reconstructed formula. It appears that the skim and wedge compounds for this tire

John Baldwin Page 5 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 20 of 168 construction are the same. It is also important to realize that the formula represents the rubber as tested, not necessarily as formulated.

RESULTS AND DISCUSSION

As stated in the introduction, the wedge rubber is one of the most important components of the tire construction related to durability. One of the more useful ways to analyze the change in properties of the wedge rubber is to utilize the data analysis method of Ahagon and coworkers, which correlates the strain ratio at break with the modulus at 100% strain8,9,10. This approach is particularly useful in distinguishing between different aging mechanisms. By plotting the log of the strain ratio at break vs. the log of the modulus at 100% strain, a straight line with a slope of -0.75 is indicative of the aerobic aging of rubber. This approach was arrived at by taking one compound with different levels of sulfur and measuring the stress-strain data. The same compound (at one level of sulfur) was then oxidatively aged and it was shown that the stress strain data behaved identically to the compounds with increased sulfur. Thus, the mechanism of oxidative aging was inferred to consist of increased crosslink formation. High temperature aerobic (defined as Type III aging) or possibly anaerobic aging (defined as Type II aging) of the rubber results in data deviating from the straight-line. It is important to realize that the slope of –0.75 is an empirically derived number and more than likely dependent on the aging characteristics of the individual compound being studied. Careful reading of the referenced studies does not yield a 'first principles' reason for the slope to be any particular value. Figure 2 is a representation of how data for the various aging types would look in graphic form. Aerobically aging NR typically stress hardens, leading to lower elongation, which yields a prediction of a negative slope, given the data treatment shown. Figure 3 shows the results for the tires in the present study plotted in the manner described above. The nitrogen concentrations in the tire cavity at the beginning of oven aging for the four filling gas conditions were (in ascending order): 56% (the 50/50 N2/O2 inflation blend with 1 atmosphere of air present), 78% (air inflation), 96% (99.9% nitrogen with 1 atmosphere of air present), and 99.9% (99.9% nitrogen with the 1 atmosphere of air purged). The tires were aged at 60°C for 3-12 weeks. As can be seen in Figure 3, the wedge rubber of the tires containing >95% nitrogen experienced almost no change in stress-strain properties, even after 12 weeks in the oven, while tires filled with air or 50/50 N2/O2 experienced a substantial change after only 3 weeks of oven aging. The changes seen in the data for tires inflated with >95% nitrogen are consistent with completion of curing of the new tire, not oxidative aging. The excluded points on the graph are for tires with air and the 50/50 N2/O2 mixture at 12 weeks in the oven. The mechanism of aging has been affected by loss of oxygen due to permeability over that time and the oxidation of the wedge rubber has become limited by diffusion. An additional method used to analyze the data was to plot the normalized strain ratio at break vs. residence time in the ovens at 60°C (Figure 4). Normalized strain ratio at break is determined by dividing the strain at break of a tire aged in the oven for time t (e(t)) and dividing it by the strain at break for a new, unaged tire (e(0)). The results in Figure 4 show that for tires inflated with >95% nitrogen there is an initial drop in strain at break. The reason for that could again be

John Baldwin Page 6 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 21 of 168 that new tires are generally undercured and the continuation of cure was completed during the first 3 weeks in the oven. After the first 3 weeks, the results are unchanged for the durations tested, except for the point at 12 weeks oven duration and 96% nitrogen concentration. It may be that the oxygen concentration present in the tire took that long to reach the wedge in concentrations large enough to effect the strain at break properties. Again, tires filled with air or 50/50 N2/O2 experienced a substantial change after only 3 weeks of oven aging and continued that trend out to 12 weeks. One conclusion that is inescapable from this initial work is that the oxidation of the steel belt rubber is truly driven from the contained air pressure inside a normal passenger or light truck tire. Granted, the rate of degradation would be much higher if no halobutyl innerliner was present, but the presence of innerliner and antioxidant packages only slows the rate of degradation, not eliminate it. Peel strengths of the steel belt composites were also evaluated. The peel strength is a measure of the force required to separate the two steel belts and is a simple way to measure tearing energy11. Figure 5 shows the results of the normalized peel strength vs. log time. Normalized peel strength is determined by dividing the peel strength of a tire aged in the oven for time t (p(t)) and dividing it by the peel strength for a new, unaged tire (p(0)). As opposed to the results for the strain at break of material obtained from the wedge region of the tire, the peel strength of rubber from the much thinner skim region does degrade with time for all inflation media used in the study. The results in Figure 5 also show, however, that the tires inflated with >95% nitrogen degrade at a much slower pace than tires inflated with air or 50/50 N2/O2. The fact that tires inflated with either 96% or 99.9% nitrogen degrade almost identically lead one to believe that either oxygen is reaching the belt skim rubber from the outside of the tire or that the change in peel strength is due to a change in the crosslink density distribution not detected in the wedge material properties. Both mechanisms are being investigated and will be reported in future work. Oxygen uptake measurements are being taken on the skim stock to determine whether oxygen is reaching the area from another source and crosslink distribution measurements are being made to determine if any sulfur rearrangements have occurred. The data shown in Figure 5, however, all appear to be changing according to the same mechanism. If that is true, then one should be able to shift the data according to a time-pressure superposition method to determine the acceleration of the degradation mechanism present. Ferry has shown that ultimate properties can be analyzed using reduced variables and shifted with respect to temperature or pressure12. In this case, the partial pressure of oxygen is different between the four conditions analyzed. Figure 6 is a graph of the normalized peel data whereby the data for tires inflated with air or 50/50 N2/O2 are shifted along the x-axis to line up with data from tires inflated with >95% nitrogen. The data shifts overlap and appear to have an excellent fit to a logarithmic regression. This fact suggests that the change in the peel strength for nitrogen inflated tires is caused by oxidation in the skim rubber, not by changes in the crosslink distribution. One could infer from the shift factor between air and nitrogen inflation that tires inflated with nitrogen would take twice as long to deteriorate as air inflated tires would. While this may be true at 60°C, the magnitude of improvement may be lessened if the data was shifted down to temperatures that tires operate at normally. The discrepancy would be caused by possible diffusion limited oxidation effects at 60°C vs. ambient temperature. The

John Baldwin Page 7 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 22 of 168 concentration of oxygen diffusing into the tire may be sufficiently low enough in the oven so that it never reaches the wedge and only small amounts reach the skim because at elevated temperatures the oxygen reactivity is increased. At ambient temperature, however, more oxygen may reach the skim and perhaps even reach the wedge. This is not to say that tire oxidation is not driven by the inside air pressure, just that in the absence of inside air pressure, oxidation in the wedge and skim regions may occur from outside air and the rate could be higher than what is reported at 60°C. Nonetheless, it is perhaps a fair assumption to say that there would be some improvement in tire durability if nitrogen was used as the inflation media, but it is too soon to speculate as to how much of an improvement it would be.

John Baldwin Page 8 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 23 of 168

CONCLUSIONS

The overall conclusion of the study is: When N2 is used as the inflation media, the change in rubber properties is significantly slowed down or even halted. From a practical standpoint it is important to note that the presence of 1 atmosphere of air in the 96% nitrogen inflated tires did not significantly affect the results, as compared to the 99.9% nitrogen inflated tire. This is important for the average consumer because the need to purge existing tires completely of air before filling with nitrogen may not be necessary. Another conclusion is that the oxidation of the steel belt rubber is truly driven from the contained air pressure inside a normal passenger or light truck tire. The skim region may be oxidized slightly from outside the tire when filled nitrogen, but the rate of degradation is significantly lower than when the tire is filled with air. The wedge rubber, on the other hand, is in a sufficiently thick part of the tire, and is not nearly as susceptible to oxidation from the outside. The converse of this conclusion, therefore, is that oxidative aging can be accelerated by the use of oxygen enriched filling gases in the tire cavity without changing the mechanism of degradation in the tires internal components.

ACKNOWLEDGEMENTS The authors wish to thank Mr David Connaughton from Parker Balston Corporation for supplying the nitrogen filtering equipment and the oxygen concentration sensor used for this study. The authors would also like to thank Mr. Uday Karmarkar and Mr. Robert Samples from the Akron Rubber Development Laboratory for their help in project management and general counseling during this work.

John Baldwin Page 9 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 24 of 168 Captions For Figures and Tables

Table 1 – Chemical reconstruction of the wedge rubber compound found in the tires used in this study.

Figure 1 – Tire nomenclature used in this paper.

Figure 2 – Data analysis ('Ahagon Plot') used to understand aging mechanism of wedge rubber. The plot is of the log of the strain ratio @ break vs. the log of the modulus @ 100% strain. Linear Type I aging is considered normal, oxidative aging. Type II aging is considered high temperature, anaerobic aging. The mechanism for Type III is high temperature oxidative aging, which could also be called diffusion limited oxidation (DLO).

Figure 3 – Ahagon plot for tires oven aged at 60°C with air, 50/50 N2/O2, 96% nitrogen, and 100% nitrogen as the inflation media. The tires inflated with >95% nitrogen do not appear to change very much from the new tires, even after 12 weeks in the oven, whereas tires inflated with the oxygenated media change dramatically, even after 3 weeks in the oven.

Figure 4 – Normalized strain @ break vs. time for tires oven aged at 60°C with air, 50/50 N2/O2, 96% nitrogen, and 100% nitrogen as the inflation media. Again, tires inflated with >95% nitrogen do not appear to change very much from the new tires. The exception is the data for tires at 12 weeks inflated with 96% nitrogen. The beginning of oxidative degradation can be seen. Nitrogen inflated tires, however, degrade far slower than tires inflated with the oxygenated media.

Figure 5 – Normalized peel strength vs. time for tires oven aged at 60°C with air, 50/50 N2/O2, 96% nitrogen, and 100% nitrogen as the inflation media. The results show that tires inflated with >95% nitrogen degrade at a much slower rate than tires inflated with air or 50/50 N2/O2.

Figure 6 – A graph of the normalized peel data whereby the data for tires inflated with air or 50/50 N2/O2 are shifted along the x-axis to line up with data from tires inflated with >95% nitrogen. The data shifts overlap and appear to have an excellent fit to a logarithmic regression. This fact suggests that the change in the peel strength for nitrogen inflated tires is caused by oxidation in the skim rubber, not by changes in the crosslink distribution.

John Baldwin Page 10 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 25 of 168 Figures

Figure 1

John Baldwin Page 11 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 26 of 168

Figure 2

John Baldwin Page 12 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 27 of 168 0.9

0.85 y = -0.8903x + 1.331 R2 = 0.9116 0.8

0.75 eak r 0.7 @ B

tio 0.65 Ra New rain t 0.6

g S Air Lo 0.55 50/50 96% N2 0.5 100% N2

0.45 Points Excluded From Regression.

0.4 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 Log Modulus @ 100% Strain (MPa)

Figure 3

John Baldwin Page 13 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 28 of 168 1.2

(t)/e(0) 0.8

k (e Air

ea y = -0.0909Ln(x) + 0.919 r Air R2 = 0.9925 50/50

@ B 0.6 96% N2

rain 50/50 100% N2

St y = -0.1882Ln(x) + 1.0196 R2 = 0.9739 lized

a 0.4 rm No

0.2

0 110100 Log Time (weeks)

Figure 4

John Baldwin Page 14 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 29 of 168 1

0.9

96% Nitrogen 0.8 y = -0.1769Ln(x) + 1.0756 R2 = 0.9319 0.7 th

ng 100% Nitrogen 0.6 y = -0.1993Ln(x) + 1.108 Stre Air R2 = 0.9081 eel 0.5 50/50 P d 96% N2

lize 50/50 a 0.4 y = -0.2528Ln(x) + 1.0234 100% N2 2

Norm R = 0.9156 Air 0.3 y = -0.2501Ln(x) + 1.0592 R2 = 0.9807 0.2

0.1

0 110100 Log Time (weeks)

Figure 5

John Baldwin Page 15 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 30 of 168 1

0.9 Shift Factors: 96% N2 = 1 100% N2 = 1 0.8 Air = 2 50/50 = 3 0.7 h

ngt 0.6

stre 96% N2

eel 0.5 100% N2 P Air lized

a 0.4 50/50

Norm y = -0.2122Ln(x) + 1.5595 0.3 R2 = 0.9378

0.2

0.1

0 10 100 1000 Shifted Log Time (days)

Figure 6

John Baldwin Page 16 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 31 of 168

Tables

Ingredient PHR Extractables Ash Volume Polyisoprene 100 1.0 107.5 Carbon Black (N326) 61 33.9 Zinc Oxide 6.7 6.7 1.2 Calcium Carbonate 1.0 1.0 0.4 Dioctyl Adipate 1.0 1.0 1.0 Hydrocarbon Oil 5.4 5.4 5.5 Cobalt Napthenate 0.5 0.1 0.1 0.5 Wax 1.0 1.0 1.0 Stearic Acid 1.0 1.0 1.2 Santoflex 6PPD 2.0 2.0 1.7 Misc. Extractables* 1.0 1.0 1.1 Santocure NS 1.5 0.3 1.0 Sulfur 2.3 1.2

Total 184.4 12.8 7.8 157.2

Calculated Ash Content (by wt.) 4.2% Calculated Extractables (by wt.) 6.9% Calculated Carbon Black (by wt.) 33.1% Calculated Density (mg/ml) 1.173

* Formulation may contain processing aids, waxes, etc.

Table 1

John Baldwin Page 17 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 32 of 168 References

1 D. M. Coddington, RUBBER CHEM. TECH., 52, 905, (1979)

2 Engineering Analysis Report and Initial Decision Regarding EA00-023: Firestone Wilderness AT Tires, http://www.nhtsa.dot.gov/hot/Firestone/firestonesummary.html

3 J.M. Baldwin, M.A. Dawson, and P.D. Hurley, "Field Aging Of Tires, Part I", presented at a meeting of the Rubber Division, American Chemical Society, Cleveland, OH, October 14-16, 2003.

4 J.M. Baldwin, "Accelerated Aging Of Tires, Part I", presented at a meeting of the Rubber Division, American Chemical Society, Cleveland, OH, October 14-16, 2003.

5 J.M. Baldwin, David R. Bauer, and Kevin R. Ellwood, "Accelerated Aging Of Tires, Part II", presented at a meeting of the Rubber Division, American Chemical Society, Grand rapids, Mi, May 17-19, 2004.

6 L. R. Sperberg, Rubber Age, 99 (11), 83 (1967)

7 7 N. Tokita, W. D. Sigworth, G. H. Nybakken, and G. B. Ouyang, Int. Rubber Conf., Kyoto, Oct 15-18, 1985.

8 H. Kaidou, A. Ahagon, RUBBER CHEM. TECH., 63, 698 (1990).

9 A. Ahagon, RUBBER CHEM. TECH., 59, 187 (1986).

10 A. Ahagon, M. Kida, and H. Kaidou, RUBBER CHEM. TECH., 63, 683 (1990).

11 M.A. Dawson, and J.M. Baldwin, "Peel Adhesion As A Measure Of Rubber Properties For Steel Belted Radial Tires", presented at a meeting of the Rubber Division, American Chemical Society, Cleveland, OH, October 14-16, 2003.

12 "Viscoelastic Properties Of Polymers", J. D. Ferry, Chapter 11, John Wiley & Sons, 1980

John Baldwin Page 18 5/26/2004

FOR USE BY PURGEN98 DEALERS ONLY Page 33 of 168

______PRISM Membranes Telephone (314) 995-3300 Air Products and Chemicals, Inc. Fax (314) 995-3500 11444 Lackland Road www.airproducts.com/membranes St. Louis, MO 63146-3544

Mr. Gil Schoener President Branick Industries 4245 Main Avenue Fargo, ND 58107

November 18, 2004

Dear Gil:

This is in response to your request for a review of scientific principles relating to the use of nitrogen as a gas for tire inflation.

1. Why does oxygen migrate out of tires quicker than nitrogen? 2. Why does nitrogen not expand and contract as much as air?

Answers:

1. Oxygen migrates out quicker than nitrogen, because: a. Permeability coefficients measured for oxygen, P O2 , are higher than the values for nitrogen, P N2 , in all known rubbers (elastomers), including those typical of tires. The ratio of the permeability coefficients, P O2 divided by P N2 , is between 3 and 4 depending on the particular rubber. This means that oxygen permeates 3 to 4 times faster through rubber than does nitrogen, other conditions being equal; b. oxygen is a smaller molecule than nitrogen (as determined by a wide variety of measurements of molecular size); this is true despite the fact that molecular weight of O2 (32) is greater than that of N2 (28), which might suggest that oxygen is larger than nitrogen; c. relative permeabilities for oxygen and nitrogen are dominated by the difference in size of the molecules.

2. There is no significant difference in expansion and contraction characteristics of nitrogen, compared to air, when moisture is absent. a. Expansion or contraction of either air or nitrogen occurs to very similar extent, in response to changes in temperature, in the commonly encountered range of temperatures and pressures relevant to discussion of tire inflation.

FOR USE BY PURGEN98 DEALERS ONLY Page 34 of 168 b. There is no practical difference as long as the gases are dry, with respect to the effect of temperature on pressure in an essentially fixed volume container, such as in a tire. c. Water is usually present in the case for conventional compressed air. At lower temperatures, as a liquid, water occupies very little volume. However, as temperature increases, liquid water vaporizes to become a gas and its volume expands, causing total pressure to be higher in the tire, than would be the case with dry gas. Thus, the presence of water in a tire contributes to pressure variations as temperatures change.

Please find attached several pages of more detailed information. I provide a Summary, explaining in plain language several factors at play in tires, comparing using Nitrogen to using conventional compressed air. In Appendix, I provide more detailed technical information drawn from credible literature sources.

If I may be of further assistance, please contact me or our Sales/Marketing Specialists, Bill Phelps and Phil Powell in St. Louis.

M. Keith Murphy, PhD Air Products Research Associate (314) 995-3434 [email protected]

FOR USE BY PURGEN98 DEALERS ONLY Page 35 of 168 Summary - Nitrogen compared to conventional compressed air for tire inflation

Benefits:

1. Maintain proper tire pressure longer with Nitrogen than with compressed air

2. Reduced degradation of rubber’s mechanical properties caused by oxidation, in the absence of oxygen, using Nitrogen

Composition differences between membrane-generated Nitrogen and conventional compressed air:

Oxygen and moisture are almost completely removed from air by the membrane.

Explanations for the benefits of using membrane-generated Nitrogen compared to compressed air for tire inflation

1. Better inflation pressure maintenance using Nitrogen:

Nitrogen permeation through the rubber is much slower than oxygen permeation. Measured permeability in all known rubbers is faster for O2 compared to N2, by factors ranging from 2.4 to 4.7, depending on the rubber. Permeability of gases is generally faster in some rubbers than in other rubbers, but all rubbers permeate O2 faster than N2 by a ratio of about 3 to 4. Oxygen permeates faster because it is a smaller molecule than is nitrogen. Thus, any tire filled to proper pressure will hold that pressure longer, if the higher permeability component (O2) is not in the tire in the first place.

2. Reduced oxidative degradation of rubber, because oxygen is absent, using Nitrogen: according to J. D. Baldwin, et.al., (Ford Motor Co.), in “Passenger tires inflated with nitrogen age slower”, Rubber & Plastics News, pp. 14-19, Sept. 20, 2004

Oxygen chemically reacts with rubber, causing the rubber’s mechanical properties to degrade. Nitrogen does not react with rubber. If oxygen is absent or present at much lower concentration, rubber mechanical properties are more stable over time.

FOR USE BY PURGEN98 DEALERS ONLY Page 36 of 168 Do tires run cooler ?:

Tire run temperature is influenced by many factors, including: Proper inflation Rolling resistance Road conditions Speed Outside environment temperature Vehicle load

Temperature influences gas pressure. Heating a gas in a fixed volume container increases gas pressure (P1/T1 = nR/V = P2/T2) and cooling decreases gas pressure. For example, a truck tire filled to 100 psig at 60F, increases in pressure to ~118 psig at 140F; a car tire filled to 30 psig at 60F will increase in pressure to ~ 37 psig at 140F. For temperatures and pressures near common experience, air, or O2 or N2, all behave very similarly in this respect. Thus, there is no significant difference in pressure changes, comparing air and N2, due to gas temperature effects alone (that is, as long as either gas is “dry”).

Water, however, can exist as liquid or as vapor (i.e., a gas) and water changes from liquid to vapor over the relevant range of temperatures. The “vapor pressure” of water is very sensitive to temperature, increasing from 0.26 psi at 60F to 2.89 psi at 140F. If there is liquid water in the tire at 60F, as does occur with conventional compressed air, water’s vapor pressure contributes a small additional amount to pressure at 140F. If dry air or dry N2 is used to fill the tire, the effect of water on pressure is eliminated.

Tire heating will be greater, if proper inflation pressure in not maintained.

Over time, a tire filled with air, will loose pressure faster, due to faster permeation of O2. This will contribute to under-inflation of the tire, absent frequent pressure checks. Under-inflation may contribute to excessive mechanical flexing of the tire, which will contribute to additional road resistance and frictional heating. Thus, improper inflation is a principle contributor to excessive tire heating.

Nitrogen helps better maintain proper tire inflation pressure, compared to compressed air.

Do tires wear longer?

Tire wear is influenced by many factors: Proper inflation pressure (see above discussion) Rubber’s mechanical properties are more stable, if oxygen is not present.

FOR USE BY PURGEN98 DEALERS ONLY Page 37 of 168 Appendix

Gas permeability data for various rubbers (elastomers)

FOR USE BY PURGEN98 DEALERS ONLY Page 38 of 168

FOR USE BY PURGEN98 DEALERS ONLY Page 39 of 168

FOR USE BY PURGEN98 DEALERS ONLY Page 40 of 168

FOR USE BY PURGEN98 DEALERS ONLY Page 41 of 168

FOR USE BY PURGEN98 DEALERS ONLY Page 42 of 168

Calculation of the approximate time required for permeation to result in a significant decrease in tire pressure, assuming case of a typical truck tire inflated with air at 100 psig initially.

This calculation uses “reasonable approximate or typical” values of tire size (volume and sidewall area available for permeation), sidewall thickness, Permeability Coefficients for gases in a “typical” rubber (elastomer), and effects of temperature on permeation rates.

The resulting time is ~11 to 53 days, depending on temperature, for a roughly 1/3rd or 7 psi decrease in partial pressure of Oxygen (initially present as about 21 psi of the 100 psi total pressure, decreasing to 14 psi oxygen partial pressure after calculated number of days). During that time a small additional pressure decrease occurs, due to the slower permeation of some nitrogen.

Thus, a tire initially inflated with compressed air to 100 psig will drop in pressure by about 7-8 psi over a few weeks, due to the oxygen permeation effects alone.

These calculations are approximate. Variations in the resulting times for pressure decreases will occur in a real situation. Actual Permeability Coefficients, area available for permeation and effective thickness of the side wall portion of the tire may differ somewhat, depending on actual tire structure, tire dimensions and the characteristics of the rubber of the tire, including effects of fillers such as carbon black in the rubber composition, and whether the rubber is reinforced with relatively impermeable non-rubber components, such as threads of nylon cord or steel.

This calculation appears to be of sufficient validity within reasonable confidence limits. It suggests practical implications, regarding the effects of permeation in the case of tire inflation pressure versus time, and supports a case for tire inflation using nitrogen as beneficial compared to using compressed air.

This calculation simply verifies, using reasonable assumptions, that a practically relevant pressure decrease can be expected to occur, due to permeation of oxygen, if compressed air is used. It also demonstrates that if Nitrogen is used instead, it would take a much longer time for a similar significant pressure decrease to occur, due to permeation effects.

Thus, inflating a tire with Nitrogen, instead of compressed air, provides significantly better maintenance of proper tire pressure.

FOR USE BY PURGEN98 DEALERS ONLY Page 43 of 168

FOR USE BY PURGEN98 DEALERS ONLY Page 44 of 168 FOR USE BY PURGEN98 DEALERS ONLY Page 45 of 168 CHAPTER III

INFLATION WITH DE-OXYGENATED AIR

3.1 GENERAL NOTIONS

In the previous chapters we demonstrated the importance of correct inflation to ensure the performance specifications for the tyre, such as high contact friction (for effective road holding, good handling and acceleration and short stopping distance), low fuel consumption, low and even wear, etc. This chapter will show that a tyre inflated with de-oxygenated air loses pressure at half the speed of a tyre inflated with air.

3.2 INFLATION WITH DE-OXYGENATED AIR

To treat the problem analytically, we must make a few simplifying assumptions: • The de-oxygenated air is assumed to contain only molecular nitrogen 1 (N2) ; • The diffusion of oxygen is assumed to be equal to that of nitrogen (that is, D ≅ D ); O2 N2 • The casing material is composed of poly-isoprene; • The permeability of the gases (oxygen and nitrogen) in poly-isoprene given in the tables has been measured at 25°C. • In studying the problem we make use of a simplified geometry (see figure 3.2.1). If we define pi1 to be the pressure at the casing/interior boundary, pi2 that at the casing/atmosphere boundary, Pi the permeability, l the casing " thickness and n& the flux of gas through the casing per unit of time and surface area, we have:

1 As will be shown in chapter IV, de-oxygenated air is indeed very largely composed of nitrogen (approx. 99 % nitrogen, 1 % other gases).

FOR USE BY PURGEN98 DEALERS ONLY Page 46 of 168 p − p n" = P i1 i2 . (eq.1) & i l

fig.2.1: Pressure p [Pa] and temperature T [°C]

PRESSIONE = PRESSURE TEMPERATURA = TEMPERATURE INTERNO DEL PNEUMATICO = TYRE INTERIOR ATMOSFERA = ATMOSPHERE MESCOLA = CASING MATERIAL

FOR USE BY PURGEN98 DEALERS ONLY Page 47 of 168 TRATTO DIPENDENTE DALLA DIFFUSIVITA’ = SECTION AFFECTED BY DIFFUSION DISTANZA = DISTANCE

From the tables, the permeability to oxygen is:

3 − cm (STP)⋅cm P = 4.6⋅10 13 , O2 cm2 ⋅ s ⋅ Pa

where (STP) signifies standard temperature and pressure, while for nitrogen we have:

3 − cm (STP)⋅cm P =1.6⋅10 13 . N2 cm2 ⋅ s ⋅ Pa

If we now call the total internal pressure p , the outer totint

(atmospheric) pressure pext , and assuming that the tyre is inflated with de-oxygenated air and that the casing thickness is constant and equal to l = 1 cm, we obtain:

5 TYRE INTERIOR: pTOT int = 3 bar = 3·10 Pa; N2 = 100 % = 1;

5 EXTERIOR (ATMOSPHERE): pext = 1 bar = 1·10 Pa; N2 = 80 % = 0.8; O2 = 20 % = 0.2;

∆p = (3⋅1) − (1⋅0.8) = 2.2bar = 2.2⋅105 Pa N2

and, from (equ.1):

∆p ⋅ 5 3 " N2 −13 2.2 10 −8 cm (STP) N = = ⋅ = ⋅ . n& 2 Pi 1.6 10 3.5 10 2 l 1 cm ⋅ s

In the case of inflation with de-oxygenated air, the deflation due to casing permeability is counteracted by a flux of oxygen into the tyre. To evaluate the value of this flux we calculate ∆p and, from (equ.1), we O2 " obtain n& O2 :

∆p = 0 − 0.2 = −0.2bar = −0.2⋅105 Pa = −2⋅104 Pa O2

FOR USE BY PURGEN98 DEALERS ONLY Page 48 of 168

∆p − ⋅ 4 3 " O2 −13 2 10 −8 cm (STP) O = = ⋅ ⋅ ≅ − ⋅ . n& 2 Pi 4.6 10 1 10 2 l 1 cm ⋅ s

The flux inward is in any case smaller than the outward flux, and hence the tyre will deflate over time. The total outward flux is given by:

3 " " " −8 −8 −8 cm (STP) tot = N + O = ⋅ − ⋅ = ⋅ n& n& 2 n& 2 3.5 10 1 10 2.5 10 2 cm ⋅ s

3.3 INFLATION WITH AIR

If we maintain the assumptions of the previous paragraph (casing " material, permeability values,...), we can recalculate the values of n& N2 " and n& O2 in the case in which the tyre is inflated with air:

5 TYRE INTERIOR: pTOT int = 3 bar = 3·10 Pa; N2 = 80 % = 0.8; O2 = 20 % = 0.2;

5 EXTERIOR (ATMOSPHERE): pext = 1 bar = 1·10 Pa; N2 = 80 % = 0.8; O2 = 20 % = 0.2;

∆p = (3−1) ⋅0.8 = 1.6bar = 1.6⋅105 Pa N2

∆p ⋅ 5 3 " N2 −13 1.6 10 −8 cm (STP) N = = ⋅ = ⋅ n& 2 Pi 1.6 10 2.6 10 2 l 1 cm ⋅ s

∆p = (3−1)⋅0.2 = 0.4bar = 0.4⋅105 Pa = 4⋅104 Pa O2

FOR USE BY PURGEN98 DEALERS ONLY Page 49 of 168 ∆p ⋅ 4 3 " O2 −13 4 10 −8 cm (STP) O = = ⋅ ⋅ = ⋅ , n& 2 Pi 4.6 10 1.8 10 2 l 1 cm ⋅ s

and hence the total outward flux in case of inflation with air is given by:

3 " " " −8 −8 −8 cm (STP) tot = N + O = ⋅ + ⋅ = ⋅ n& aria n& 2 n& 2 2.6 10 1.8 10 4.4 10 2 . cm ⋅ s

3.4 CONCLUSIONS

From the above it is evident that a tyre inflated with de-oxygenated 3 " −8 cm (STP) tot = ⋅ air (n& 2.5 10 2 ) deflates more slowly than one inflated cm ⋅ s 3 " −8 cm (STP) tot = ⋅ with air (n& aria 4.4 10 2 ), in the ratio: cm ⋅ s

" n aria & ≅ 2 . n" &N2

Let us now calculate the drop in inflation pressure of the tyre in the two cases under consideration (inflation with air and with de- oxygenated air), in a month. This calculation requires us to make further simplifying assumptions in addition to those introduced in paragraph 3.2: • During the month in question, we assume that the vehicle is not in use and is stored at a constant ambient temperature of 25°C; • We consider the gases in question (air and de-oxygenated air) to be ideal; • We will neglect the change in pressure in the tyre’s interior over time (that is, the fact that as the tyre deflates its internal pressure drops). The latter hypothesis is an admissible approximation because, as the result of the calculation will show, the percentage variation in inflation pressure is very low (a few percent). We will use the simplified geometry2 of figure 3.4.1.

2 Being a comparison, it is not necessary to calculate the exact tyre size: just define the approximate dimensions and make sure the same are used for both cases.

FOR USE BY PURGEN98 DEALERS ONLY Page 50 of 168

fig.3.4.1: Exchange boundary (heavy line)

The surface Aexchange of the tyre through which the gas flows is given by:

 D  2  D  2  = ⋅π ⋅  1  −  2  + ⋅π ⋅ ()⋅ = A exchange 2   2 D1 d  2   2    4702  400 2  = 2 ⋅π ⋅   −    + 2 ⋅π ⋅ ()470 ⋅ 300 =  2   2   = 9.8⋅105 mm 2 = 9.8 ⋅103 cm2

while the volume V is given by:

 D 2  D 2   4702  4002  V = π ⋅  1  −  2   ⋅d = π ⋅   −    ⋅300 =  2   2    2   2   = 14.3⋅106 mm3 = 14.3⋅10−3 m3 .

FOR USE BY PURGEN98 DEALERS ONLY Page 51 of 168 If we call tm the number of seconds in a month, that is:

s h days s t = 3600 ⋅ 24 ⋅ 30 = 2.6 ⋅106 , m h day month month

we can estimate the outward flux of gas in a month.

• Inflation with air:

3 " = ⋅ −8 cm (STP) n& tot air 4.4 10 cm2 ⋅s

3 = " ⋅ = ⋅ −8 ⋅ ⋅ 3 = ⋅ −4 cm (STP) n& tot n& tot Aexchange 4.4 10 9.8 10 4.3 10 air air s

n = n ⋅2.6⋅106 = 4.3⋅10−4 ⋅ 2.6⋅106 = 1118cm3 (STP) month air & tot air

Using the ideal gas law:

p·V = n·R·T

and recalling that the volume of a mole of an ideal gas is given by:

l Vm = 22.414 , gmol

It follows that the number of moles of gas initially contained inside the casing is:

p ⋅ V moles = init airinit. R ⋅T

5 where: pinitial = 3 bar = 3·10 Pa; V = 14.3·10-3 m3; J R = 8.31451 ; gmol ⋅ K T = 273.15 + 25 = 298.15 K;

FOR USE BY PURGEN98 DEALERS ONLY Page 52 of 168 These values apply to both cases under consideration. We therefore obtain:

3⋅105 ⋅14.3⋅10−3 moles = =1.730gmol . airinit. 8.314⋅ 298.15

The number of moles lost from the casing in a month is given by:

−3 n 1118⋅10 − moles = month air = = 5⋅10 2 gmol . airout Vm 22.414

The final pressure pfin is thus:

(moles − moles )⋅R ⋅T (1.730 − 5⋅10−2 )⋅8.314⋅ 298.15 p = airinit. airfin = = fin V 14.3⋅10−3 = 2.91⋅105 Pa .

We can therefore assert that in the case of inflation with air, the internal pressure drops by around 3% over a month.

• Inflation with de-oxygenated air: We use the same calculation as for the previous case: 3 " −8 cm (STP) tot = ⋅ n& 2.5 10 2 cm ⋅ s

3 = " ⋅ = ⋅ −8 ⋅ ⋅ 3 = ⋅ −4 cm (STP) n& tot n& tot Aexchange 2.5 10 9.8 10 2.4 10 s

= ⋅ ⋅ 6 = ⋅ −4 ⋅ ⋅ 6 = 3 n month n& tot 2.6 10 2.4 10 2.6 10 624cm (STP).

The number of moles lost during the month is thus:

⋅ −3 = n month = 624 10 = ⋅ −2 moliout 2.8 10 gmol . Vm 22.414

And hence the final pressure pfin is:

(moli − moli )⋅ R ⋅T (1.730 − 2.8⋅10−2 )⋅8.314⋅ 298.15 p = airinit out = = fin V 14.3⋅10−3

FOR USE BY PURGEN98 DEALERS ONLY Page 53 of 168 = 2.95⋅105 Pa .

It follows that in the case of inflation with de-oxygenated air the drop in inflation pressure is 1.6% over the month.

If we compare the two results, it is evident that a tyre inflated with de-oxygenated air loses pressure at half the speed of a tyre inflated with air. Note that these results are approximated to higher figures, however the purpose of this study is to give a qualitative characterisation of the advantages of inflation with de-oxygenated air.

3.5 OTHER ADVANTAGES OF INFLATION WITH DE- OXYGENATED AIR

Slower deflation over time of tyres inflated with de-oxygenated air is the most evident, but not the only, advantage offered by this technique. For instance, a further important factor is the deterioration of the casing’s lining by the oxygen contained in air (which is currently the most commonly used inflation gas), and it follows that using de-oxygenated air does not have this disadvantage. All tyres have a service life dependent on a number of factors, including: − Deterioration of the lining due to oxidation; − Fabrication defects; − The quality of the road surface; − Formation of cracks on the outer surface of the casing due to ozone and normal oxidation. The most important of these factors, and the one which can be most simply protected against, is the deterioration of the lining due to oxidation. Note that the harmful effects of oxygen on the lining have been known and studied since the 60’s, but tyre technology has only taken these studies into account in recent years. Let us consider Arrhenius Law of chemical reaction:

− E ⋅ k = A ⋅T n ⋅ e Ro T

where: − The term

FOR USE BY PURGEN98 DEALERS ONLY Page 54 of 168 − E ⋅ A ⋅ e Ro T

is the Arrhenius coefficient; − k is the reaction speed constant; − T is temperature; − A is a constant; − n is a constant; − E is the activation energy, i.e. the minimum energy of molecular collision required to activate the chemical reaction. If we consider three substances X, Y and Z, the constant k (in the case of direct reaction) allows us to express the variation in the concentration of Z as a function of the concentrations of X and Y:

d[]Z = k ⋅ [][]X ⋅ Y dt

where [X], [Y] and [Z] are the concentrations of X, Y and Z respectively. From this we can see that the oxidation affecting the lining depends on the temperature T, the concentration of oxygen in the inflation gas and the time t. Since the state S of deterioration of the tyre has a limit – beyond which the tyre must be replaced – and since, as we have seen:

S ∝ T, t, concentration ; S = constant O2

it follows that by reducing the temperature or concentration of the oxygen we increase the life of the tyre. As shown in Chapter II, reducing heat generation inside the casing is extremely difficult and requires changes in the chemical composition of the material; it is very difficult to affect the temperature. It is far simpler to change the oxygen concentration inside the tyre by using de-oxygenated air as the inflation gas. During the period May 1966 to November 1967, five tests were run in the United States on private car and truck tyres to investigate the phenomenon of oxidation. Each test when run for half of its duration using tyres inflated with air, for the other half with inert gases so as to reduce the concentration of oxygen. A sixth test was run for 36 months (November 1964 to November 1967) on 80 truck tyres to evaluate the effect of oxidation in the inner tube. All six tests clearly demonstrated that using de-oxygenated air as the inflation medium had a positive effect on the life and wear of the tyre. The results demonstrated that if

FOR USE BY PURGEN98 DEALERS ONLY Page 55 of 168 the oxygen concentration inside the tyre is reduced by 6%, the life of the private car tyres was increased by 22 %, and that there was an evident reduction in wear. From this we can calculate that using de-oxygenated (completely oxygen-free) air for inflation would increase average tyre by 25 % in the case of private cars and 40-50% for trucks. At the time of writing, these tests have been repeated a number of times on a variety of vehicles. We can state that the use of tubeless tyres – as compared to the tubed tyres in use in the 1960’s – make the advantages of using de-oxygenated air even more evident: in this case the average life of private car tyres is increased by 48%, while the life of truck tyres is increased by 26 %. We must emphasise that if the tyre is inflated with de-oxygenated air, the tyre is subject to reduced deterioration and this results in the possibility of making a larger number of repairs on truck tyres3: while using air enables us to make 3 - 4 structural repairs, using de- oxygenated air increases this number to 6 - 7 repairs. Directive EC/94/95 of the Council dated 21 November 1994 (harmonisation of the legislation of the member states regarding the transport of hazardous goods by road) provides that use of de- oxygenated air for tyre inflation is obligatory for road vehicles transporting hazardous goods, although if the vehicle is transporting the goods only within the national boundaries of the State in which it is licensed, it must comply with the provisions of local legislation.

3.6 THE TYRE MANUFACTURERS’ VIEW OF INFLATION WITH DE-OXYGENATED AIR

We quote below the declarations of a number of tyre manufacturers regarding tyre inflation with de-oxygenated air.

“Many manufacturers of industrial and earth moving machines recommend inflation with nitrogen as it reduces the danger of explosion due to excessive external heating, such as:

– The vehicle catching fire;

– Too abrupt braking;

– Extended brake application;

3 Since trucks have a very high annual mileage their tyres wear very quickly and, to avoid the high costs associated with replacing the entire set of tyres, it is customary to repair the tread so long as the sidewalls are still in good condition.

FOR USE BY PURGEN98 DEALERS ONLY Page 56 of 168 – Welding of the rims with the tyres installed. All of these factors can provoke the ignition and burning of the interior of the tyre. An explosion due to tyre combustion is far more powerful than a tyre burst. Such explosions can cause serious injury and death. […] inflation with nitrogen has numerous other advantages:

– It maintains tyre pressure better;

– It reduces aging due to casing oxidation;

– It minimises rust formation on the rim.” Good Year

“Air contains both nitrogen and oxygen. Oxygen diffuses through the casing much faster than nitrogen. A tyre inflated with nitrogen loses pressure at a third of the rate of one inflated with air. Tyres inflated in this way thus require much less frequent checking and also are far less likely to be damaged by insufficient inflation. The use of nitrogen also reduces casing oxidation and the consequent deterioration of the tyre. Nitrogen also reduces rim corrosion and thus makes disassembly easier. […] this type of inflation [with nitrogen] is recommended especially for the following applications:

– Use in explosive atmospheres;

– Use on, or in proximity to, incandescent materials (foundries, steelworks, glassworks, etc.);

– Use in conditions of electrical sparking hazard (high tension lines and cables);

– Use with risk of tyre overheating due to: -Intensive use (speed, distance, intensive duty cycles); -High transmission of heat from the brakes and engine.”

Michelin

“[…] we give below the main characteristics of nitrogen compared to compressed air and the specific advantages for tyre inflation, as well as some general considerations. 1. Nitrogen is oxygen-free: the absence of oxygen in the tyre reduces the speed at which the casing material ages, with beneficial effects on the condition of the casing itself; 2. Industrial nitrogen is dry: the gas used for tyre inflation is almost completely dry and free of carbon dioxide. This eliminates or

FOR USE BY PURGEN98 DEALERS ONLY Page 57 of 168 minimises the rubber/metal corrosion due to the water vapour in compressed air, and improves the life of the metal belt (and in the case of industrial vehicles, also the life of the casing); 3. Nitrogen increases the life of the materials with which it is in contact: compared to compressed air, the absence of oxygen, CO2, dust and other impurities protects the valve […]; 4. Impermeability: the casing material […] is more permeable to oxygen than to nitrogen […]; 5. Tyre working temperature: the working temperature of the tyre is not appreciably affected by the use of nitrogen rather than air for inflation; 6. Cost: the cost of production of nitrogen is generally higher than that of compressed air, although this difference will be reduced as the use of nitrogen becomes more widespread[…]; 7. Explosion / fire hazard: unlike air, nitrogen does not cause the risk of explosion or fire, being inert and non-flammable; 8. Environment: nitrogen has no negative environmental effects: the air we breath is 80 % nitrogen; (nitrogen) does not contain oil, which is present in compressed air; 9. Tyre mounting/demounting criticalities: The use of this gas does not incur any particular criticalities inasmuch as it disperses on contact with the air. Nonetheless, it should not be used in small closed areas where it might reduce the normal concentration of oxygen.” Pirelli

FOR USE BY PURGEN98 DEALERS ONLY Page 58 of 168 FOR USE BY PURGEN98 DEALERS ONLY Page 59 of 168 News Release from the Tire Retread Information Bureau/Nitrogen Inflation for Tires TRIB TIRE RETREAD INFORMATION BUREAU 900 WELDON GROVE PACIFIC GROVE, CA 93950 USA 831-372-1917 • FAX 831-372-9210 TOLL FREE FROM ANYWHERE IN NORTH AMERICA 888-473-8732 EMAIL: [email protected] NEWS RELEASE ABOUT TIRES

Why Inflating Tires With Nitrogen Makes Sense

For Immediate Release PACIFIC GROVE, CA, August 2005 Contact: Harvey Brodsky, (831) 372-1917 The practice of inflating tires with nitrogen has been around for a long time. Because of the benefits of nitrogen over air, is has been commonly used in tires on aerospace vehicles, commercial and military aircraft, racecars and off-road equipment.

With advances in technology and the expanding commercial infrastructure of nitrogen availability, nitrogen inflation is a growing trend in the transportation industry.

This article by the Tire Retread Information Bureau (TRIB), provides a primer and overview of nitrogen inflation, and discusses how it helps optimize tire costs while providing environmental benefits.

TRIB is a non-profit, member-supported industry association dedicated to the recycling of tires through retreading and repairing, and to promoting proper tire maintenance for all tires.

FOR USE BY PURGEN98 DEALERS ONLY Page 60 of 168 By far, the single most critical factor for maximizing tire life and minimizing the chance of catastrophic tire failure is maintaining the proper inflation pressure for a given tire size and load. Properly inflated tires not only last longer, but also are safer.

One way to help maintain proper tire inflation is to fill tires with nitrogen instead of compressed air. Nitrogen allows a tire to retain more of its original properties.

Among the benefits of nitrogen inflation: less inflation pressure loss for a more stable, consistent tire pressure; cooler running tires; longer tread life; less oxidation of tire components, and reduced rim and wheel corrosion. The result is increased tire life, improved fuel economy, reduced tire aging and a more durable casing for improved retreadability.

While the trend toward nitrogen inflation is relatively “new” to the truck and bus tire market, it has been long used in tires on Formula One, Indy, Le Mans and NASCAR racecars; commercial and military aircraft; military vehicles; heavy off-road construction equipment, and the Space Shuttle. The Moon Buggy had its tires inflated with nitrogen. Also, the Tour de France bikes use nitrogen in their tires. Nitrogen is environmentally safe and non-combustible. A reason for the slow growth of nitrogen tire inflation in on-highway transportation has been the availability of nitrogen. However, more and more nitrogen filling facilities are appearing nationwide as on-site nitrogen generators have become more affordable and as more manufacturers of nitrogen generators have entered the marketplace. THE SCIENCE

Over time the pressurized air inside a tire slowly migrates and permeates its way into and through the tire. Air contains moisture. So in addition to reducing the tire’s inflation pressure, the oxygen and moisture in the air reacts with the rubber compounds in the tire, causing them to break down and lose their strength and durability. A chart is available illustrating that nitrogen is the slowest of all gases to flow through a permeable barrier such as a tire. For a copy of the chart please contact us at the number or email address shown above.

An underinflated tire is much more prone to premature failures. That’s because when underinflated, as a tire rolls, it flexes more than it was designed to. This flexing bends the tire’s rubber and steel (used within the rubber to provide additional operating characteristics) and

FOR USE BY PURGEN98 DEALERS ONLY Page 61 of 168 generates heat. Heat is a tire’s worst enemy and accelerates tire wear dramatically. There is a direct correlation between how much a tire is underinflated and how much faster it wears.

Since air, which contains oxygen, is not an inert gas, it is affected by changes in temperature, which affects the rate of air loss from a tire. The air inside a tire expands when heated and contracts when cooled. More air is lost in hot weather. The consensus is that for every 10- degree Fahrenheit change in temperature, there will be a one psi (pound per square inch) change in the pressure of a tire. Nitrogen will not fluctuate as much. Being an inert gas - not readily changed by chemical reaction, nitrogen provides constant pressure and is less susceptible to accelerated diffusion caused by changing temperatures.

Nitrogen inflation minimizes moisture and oxygen in a tire so there is less rubber degradation and no corrosive properties as found in compressed air. A reduction in rubber oxidation slows a tire’s “aging,” improving the casing’s structural durability, lengthening its useful life and yielding a higher proportion of retreadable casings that can survive more retread cycles. All of this helps lower operating costs. Some fleet managers, who had been dead set against retreads, are now willing to use retreads with nitrogen inflation.

Because nitrogen molecules are slightly larger and less permeable than oxygen and all the other gases in air, it migrates considerably slower through a tire. It might take a truck or bus tire inflated with nitrogen about three months to lose two psi, whereas even a well-maintained tire inflated with compressed air will lose, on average, about two psi per month. INFLATION CHECKS

Just because nitrogen provides consistent inflation pressure over longer periods, that doesn’t mean there is no longer a need to regularly and properly check tire pressure. Tires still need to be checked using a calibrated tire gauge and when a tire is “cold” - meaning when a tire is at approximately the same temperature as the surrounding air, typically before a vehicle has been driven, or driven less than one mile.

Kicking or thumping a tire cannot accurately estimate inflation pressure. Trying to determine if a tire needs air by thumping it is as effective as trying to determine if a vehicle’s engine needs oil by thumping on its hood.

Regardless of what is inside a tire - air or nitrogen, properly

FOR USE BY PURGEN98 DEALERS ONLY Page 62 of 168 maintaining tires maximizes tire life and fuel economy, and provides improved handling, traction, braking and load-carrying capability. By being more fuel efficient, less fuel is consumed, which decreases petroleum fuel demand and reduces emissions and pollution.

ENVIRONMENTAL BENEFITS

Nitrogen can provide stronger casings for more retreadability, and retreaded tires actively contribute to helping conserve valuable finite natural resources and reduce solid waste disposal problems. Every retread produced means one less new tire, which minimizes the number of new tires that need to be produced annually.

Production of new truck and bus tires consumes large amounts of energy and materials that impact the environment. Truck and bus tires are basically petrochemical products. It takes 22 gallons of oil to manufacture one new tire. Most of that oil is used in the tire casing, which is reused in the retreading process, where only approximately 7 gallons of oil is required to retread that same tire. So each time a tire is retreaded, approximately 15 gallons of oil are saved.

Retreading conserves hundreds of millions of gallons of oil every year, which in today’s oil-scarce world is extremely important. And because retreading requires less rubber, fewer rubber trees are “tapped,” which helps preserve the natural environment and reduces the loss of natural habitat.

To make the crude rubber used to manufacture tire, workers known as “tappers” make a shallow cut in the trunk of rubber trees and insert a “tap” - actually as small spout - with a cup underneath. Latex containing rubber drips into the cup. The latex is collected and processed into crude rubber.

By extending the useful life of a tire, retreading offers additional environmental benefits. Every tire retreaded is a tire that does not need to be disposed of.

Because every reputable truck and bus tire manufacturer designs and engineers its tires for several retreading lives, only one worn tire casing requires disposal instead of many. The natural resources that are saved and the positive impact on the environment are multiplied.

So are the cost benefits to users of retreaded tries. For most commercial vehicle fleets, tires represent the third largest item in their operating budget after labor and fuel costs. Retreading can cut tire costs in half and sometimes even more.

FOR USE BY PURGEN98 DEALERS ONLY Page 63 of 168 MIXING NITROGEN & AIR

There is some confusion about what happens when nitrogen and air are mixed inside a tire. By way of example: when a nitrogen-inflated tire needs some additional pressure and nitrogen is not available.

Normal air is about 78% nitrogen; so adding compressed air will simply drop the nitrogen purity. There shouldn’t be any adverse affects on the tire or vehicle handling, provided the pressure is kept at the proper level.

The manufacturers of nitrogen inflation system advise that any tire containing both nitrogen and air be purged and then re-inflated with the proper amount of nitrogen as soon as possible. The same procedure holds true in the event that a tire would need to be replaced and nitrogen is not available.

In a situation where a nitrogen-inflated steer tire has been repaired and refilled with air, some nitrogen inflation system manufacturers recommend that the nitrogen be let out of the other steer tire and refilled with air.

The reason, they explain, is that an air-filled tire will heat up and expand, whereas the tire with nitrogen will not, possibly causing a slight pull to the side with the nitrogen-inflated tire. With air in both steer tires, the air pressure will expand relatively equally, so there shouldn’t be any steering issues.

Here again, as soon as possible, the air should be purged from both steer tires and properly re-inflated with nitrogen. There is a small controversy over this point. There are some in the field who believe the effect of topping up nitrogen filled tire with air has too small an effect in handling terms to require such action.

For additional information, including a list of locations where nitrogen is available, contact the Tire Retread Information Bureau (TRIB) toll free from anywhere in North America at (888) 473-8732, send an e-mail to [email protected] or visit TRIB’s website at www.retread.org.

TRIB WISHES TO THANK OUR MEMBERS WHO DEAL WITH NITROGEN FOR CONTRIBUTING TO THIS ARTICLE.

FOR USE BY PURGEN98 DEALERS ONLY Page 64 of 168 Bibliography and Selected Reading

1. Airworthiness Standards: Transport Category Airplanes, 14CFR part 25.733, U.S. Code of Federal Regulations. http://ecfr.gpoaccess.gov/cgi/t/text/text- idx?c=ecfr&sid=36428fa124d2c4da59c6b875c89fac1c&rgn=div8&view= text&node=14:1.0.1.3.10.4.175.36&idno=14

2. Lawrence R. Sperberg, Million Mile Truck Tires – Available Today, Stronger Longer Tires of El Paso, Inc. El Paso, TX 1985.

3. Shell Unveils Nitrogen Tire-Inflation Systems, Associated Press, Houston, July 3, 1997.

4. Haray, K and Sun-Tak Hwang, Permeation of oxygen, argon and nitrogen through polymer membranes, Journal of Membrane Science, 71, (1992) 13-27.

5. Peacock, R.N., Practical selection of elastomer materials for vacuum seals, J. Vac. Sci. Technol. 17(1) Jan/Feb 1980.

6. Technical Information, Tire Inspection: Bridgestone/Firestone http://www.trucktires.com/us_eng/technical/bftechnical/tire_inspection_ b.asp 7. Garrot, W. Riley; What Applied Research has Learned from Industry About Tire Aging, NHTSA, 5/2003. http://www- nrd.nhtsa.dot.gov/vrtc/ca/tireaginglessons.pdf

8. Power, Stephen, Aeppel, Timothy; Many Current Models of Tires Don’t Meet New Federal Rules,The Wall Street Journal, September 5th, 2002.

9. Baldwin, J.M., Bauer, David R., and Ellwood, Kevin R., Effects of Nitrogen Inflation on Tire Aging and Performance, Rubber & Plastics News, Vol. 34, No. 4, pp 14-19, 2004.

10. Tokita, N. et al., Uniroyal, Inc; Long Term Durability of Tires, International Rubber Conference, Kyoto, Japan, October 1985.

11. Use of Nitrogen, Technical Bulletin PM-03-05, Michelin, Greenville, SC, November, 2003.

12. Use of Nitrogen as Inflation Agent for Tires, Product Service Bulletin #2004-09, Goodyear Tire and Rubber Company, Akron, OH,

FOR USE BY PURGEN98 DEALERS ONLY Page 65 of 168 June 14, 2004.

13. Fisher, Peggy, 1998 Tire Debris Survey Summary , The Maintenance Council of the American Trucking Association, 1998.

14. Walenga, Guy. Bridgestone/Firestone, Nitrogen Inflation for Truck Tires. Clemson Tire Conference. Clemson University, 11 Mar. 2004.

15. Fisher, Peggy, A New Gas for the New Millenium? , Tire Business, 7/2000.

16. G. Potts, et al., Technical Trends in Indoor Tire Testing, Rubber Division, American Chemical Society, Cleveland, OH, 10/2003.

17. The ‘Mephitic Air’ Advantage , Automotive Design and Production, pg 34, February, 2003.

18. Gerard-O’Connell, Mark Cool Running. Fleet Maintenance, pg 14, October, 2003.

19. Bridgestone/Firestone Annual Report http://www.bridgestone.co.jp/english/info/profile/pdf/07.pdf http://www.bridgestone.co.jp/ir/ar/2000/05japan.html

20. Should You Stop Putting Air in Your Tires, Real Questions, Real Answers, Bridgestone/Firestone North America, LLC, Vol. 8, Issue 3, 2003.

FOR USE BY PURGEN98 DEALERS ONLY Page 66 of 168 Save Gas: Inflate Your Tires -- With Nitrogen? | American International Automobile Dealers |

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Nov 16, 10:51 AM 2004 Tech Central Station

Save Gas: Inflate Your Tires -- With Nitrogen?

By Ralph Kinney Bennett

I’m pretty attentive to my cars. I tend to keep them a long time and try to keep them running well. But even I have to admit I don’t do a good job of checking my tire pressure.

Sure, I walk around and take a look at them when I’m at the gas station, and if they don’t seem noticeably saggy, that’s fine.

Well, that’s not a good idea. Improperly low pressure makes tires overheat and wear out much more quickly. And as we’ve all been reminded scores of times, it also causes a definite deterioration in car handling and a noticeable drop in gas mileage.

If you could see an underinflated tire rolling in slow motion you’d see why. Tortuous warping takes place as the tire meets the pavement. This puts a huge strain on the tire body itself and dramatically increases the tire’s "rolling resistance."

A properly inflated tire, on the other hand, has a much smaller contact area with the pavement. It’s "rounder" and therefore rolls more smoothly and efficiently, putting much less strain on your engine, transmission, rear axle or transaxle.

Over time tires lose their proper inflation pressure naturally (air actually escapes imperceptibly through the tires themselves) and although you the driver may not notice it, your car is gradually working harder to maintain a given speed.

I bicycle every day, so I am dramatically aware of the "drag" caused by underinflated tires. If you have a bike, let just a little air out of your tires and ride it around the block. See how much harder you have to work to move along. You use more energy and you know it. But in your car you’re somewhat isolated from your tires and the sound of your engine and unaware how much more energy (and therefore gasoline) you’re using to go a given distance.

The gas mileage gains for properly inflated tires may be more significant that you would think. Some state and federal studies have shown that motorists often are driving with tires 8 to 18 pounds under proper inflation pressure. One study showed that in a car running with tires at 24 pounds per square inch (psi), increasing tire pressure to 32 psi increased gas mileage by 3 miles a gallon. At today’s prices that’s pretty good.

Although, as I have mentioned, I’m a little recalcitrant, I do try to keep my tires inflated to the maximum pressure listed on the tire (you’ll see it in raised numbers somewhere on the sidewall of your tires).

Expert drivers in fuel economy runs have always known this and they superinflate their tires, running at 100 pounds per square inch or more. Don’t do this! It’s mucho dangerous. These guys are usually using special

file:///C|/Documents and Settings/Robin/Desktop/AIAD Article.htm (1 of 3)12/11/2005 11:11:11 AM FOR USE BY PURGEN98 DEALERS ONLY Page 67 of 168 Save Gas: Inflate Your Tires -- With Nitrogen? | American International Automobile Dealers |

tires under special conditions. Just follow the "max pressure" readings on your tires and, more important, keep checking them.

And here’s something that can help you. An old technological fix, known to the experts but not very well known to the public, can keep your tires running for long periods at ideal pressure.

It’s nitrogen. Yep. Good old nitrogen -- that unglamorous inert gas that constitutes about 78 percent of the air we breathe.

For years, over the road truckers, auto racers and the U.S. military have been filling tires on their vehicles with pure nitrogen. Here’s why.

In a tire filled with compressed air, the oxygen molecules tend to "migrate" through the wall of the tire over time. That’s why, when you open the garage to check on your aunt’s dust-covered 1980 Pontiac the tires are often flat.

But nitrogen molecules migrate 3 to 4 times more slowly than oxygen, so tires stay properly inflated longer. There are other benefits. Nitrogen retains less heat than oxygen and therefore allows tires to run cooler.

While nitrogen is dry and benign and will not combine chemically with other materials (the metal in tire rims, for instance), compressed air contains trace amounts of water and the oxygen tends to combine with other materials, causing rust and corrosion. If you were to see the inner face (the part enclosing and sealing the inside of the tire) of some fancy aluminum wheels you would be surprised at how corroded they become due to oxidation.

Tour de France bicyclists fill their tires with nitrogen. So do NASCAR, Indy and Formula One racing teams, over-the-road truckers, some fire departments and the U.S. military.

And now, in a typical example of the confluence of technology and markets, high gasoline prices and continuing concerns about tire safety are bringing about a growing interest in nitrogen.

Big discounter Costco has begun offering nitrogen fill-ups on new tires in some of its tire centers. Pep Boys has been test marketing nitro at some of its tire shops in the south. Several small tire chains in Florida, New York and Ohio are doing the same.

Branick Industries, of Fargo, N.D., one of the nation’s leading suppliers of equipment for tire, wheel and suspension services, builds a nitrogen inflation system that takes air from a garage or service center’s air compressor and passes it through an internal membrane that separates out the abundant nitrogen molecules.

The pure nitrogen is compressed and stored in this "nitrogen generator" and or a back-up tank next to it, from which tires are filled. Costco is filling new tires with nitrogen for free. Some dealers charge $2 per tire and up to $5 apiece on tires not sold by them.

It’s a safe bet you’ll be hearing more about nitro and seeing an increased availability of nitrogen fill-ups as you shop for tires or maintain your present ones. In the greater scheme of things this is no big deal. But like the improvements that have been made in the inner workings of automatic transmissions over the past 50 years it is one of those gains in efficiency that we often take for granted. It is one of those little refinements and improvements that are routine in a vigorous, free and therefore infinitely articulate market.

Originally published in Tech Central Station. Reprinted with permission.

file:///C|/Documents and Settings/Robin/Desktop/AIAD Article.htm (2 of 3)12/11/2005 11:11:11 AM FOR USE BY PURGEN98 DEALERS ONLY Page 68 of 168

Subject : Inflation Pressure Part 7 - Relationship between Tire Pressure and Fuel Consumption

There is a high possibility that incorrect tire inflation pressures may cause problems or possibly an accident while driving. Regularly in Toyo Tire Talk issues, the importance of regular and consistent tire inflation pressure maintenance has been stressed. This issue will reinforce that improper inflation pressure has a bad effect not only on safety of while driving, but also has an effect on economical matters, i.e. Fuel Consumption. The following is an example of the effect of low pressure on fuel consumption. (Sourced from a monitor test conducted by a road service company in Japan).

Test Method

Number of Test Vehicles 2 vehicles Normal passenger cars Vehicle Type (both vehicles were the same type) Engine Capacity 1500cc Inflation Pressure Vehicle A Front 2.1 kg/cm2 (30 psi / 210 kPa) * Rear 1.9 kg/cm2 (28 psi / 190 kPa) Vehicle B Front 1.6 kg/cm2 (23 psi / 160 kPa) ** Rear 1.4 kg/cm2 (20 psi / 140 kPa) * Tire inflation pressure of vehicle A was as recommended by the vehicle manufacturer. Test Condition ** Tire inflation pressure of vehicle B was reduced to 0.5kg/cm2 below that of vehicle A. Test Course and 1. Local Distance (km) 2. Highway 3. Mountain road ascent. 4. Mountain road descent. → Total : 150kms Note : The test vehicles were equipped with a flowmeter that can measure fuel consumption by "1 cc" increments. Additionally the fuel consumption of both test vehicles was measured before the test, and was almost at the same level.

FOR USE BY PURGEN98 DEALERS ONLY Page 69 of 168 Monitor Test Result

Vehicle A Vehicle B Recommended Inflation Pressures Lower Inflation Pressure than vehicle A Front : 2.1 kg/cm2 (30 psi / 210 kPa) Front : 1.6 kg/cm2 (23 psi / 160 kPa) Rear :1.9 kg/cm2 (28 psi / 190 kPa) Rear : 1.4 kg/cm2 (20 psi / 140 kPa)

= Vehicle A = Vehicle B Total running distance = 150km

Local Highway

17.1 16.2 11.2 10.7

Measurement : km / litre Measurement : km / litre Mountain Road Ascent Mountain Road Descent

31.5 29.0

7.4 7.1

Measurement : km / litre Measurement : km / litre

As can be seen from the above graphs, the mileage figures of vehicle B (running with lower tire pressures) are worse than vehicle A (equipped with correct tire pressures) in all conditions. If both vehicles continued running for 10,000 kms, the fuel consumption of vehicle B (equipped with lower tire pressures) is such that vehicle B would have wasted 42 litres of fuel under local driving conditions (please see the following graph). Fuel Consumption when both vehicles having run 10,000 km. Lost fuel = 42 litres

Vehicle B 11.2 km / litre 892 (local conditions) 10.7 km / litre (local conditions) 934 Vehicle B For your information, generally speaking when tire pressures are reduced by 1.0 kg/cm2 (15 psi / 100 kPa), fuel consumption is increased by 10% - 15%.

FOR USE BY PURGEN98 DEALERS ONLY Page 70 of 168 Conclusion

According this monitor test result, there is not such a large difference in fuel consumption between the tire with the correct inflation pressure and the tyre with the lower inflation pressure. However, taking the long term view, this small difference will expand to a large difference over time (i.e. a large loss). As mentioned in the previous Toyo Tire Talk, No.03-010 (TTT-148) "Inflation Pressure Part 5 - Can you feel a Decrease in Tire Pressure ?" , it is difficult to check if tire pressures have decreased just by looking and feel (accurate measurement is required). The following are recommended as a minimum for improving fuel consumption : 1) Check the inflation pressure of all tires (including the spare) periodically (at least monthly). 2) Inflate to the recommended inflation pressure* when tires are cold. * What is the recommended inflation pressure ? The recommended inflation pressure is that described on the vehicle's Tire Information Placard. This has been mentioned many times, and is included again in this issue for reinforcement.

To review this topic, please see the Tire Information Placard Toyo Tire Talk No. 01-008 (TTT-117).

Additionally, please do not forget that lower inflation pressures may be the cause of some problems or an accident whilst driving! To review the reasons for this, please refer to the Toyo Tire Talk No. 01-005 (TTT-114).

FOR USE BY PURGEN98 DEALERS ONLY Page 71 of 168

Carnegie Mellon Today

Carnegie Mellon News Services Home Page

Save Gas, Money and the Environment with Properly Inflated Tires

Diane Loviglio was one of eight students from Carnegie Mellon's Sustainable Earth Club to measure the air pressure in the tires of 81 cars parked on campus. "After seeing the numbers I was really surprised to see just how much properly inflated tires make a difference," she says.

Want to save hundreds at the gasoline pump? It's easy. Instead of hunting for the best price in town, try checking the air pressure in your tires. Proper air pressure results in better gas mileage, which at $3 per gallon could save you as much as $432 per year, according to an informal study conducted by Carnegie Mellon students last spring.

And if money isn't a big enough incentive, how about helping to preserve the environment? Less fuel consumption results in less carbon dioxide being emitted into the atmosphere.

If you think this is all a lot of "hot air," think again.

During Earthweek last April, eight students from Carnegie Mellon's Sustainable Earth Club—Diane Loviglio, Aurora Luchser Sharrard, David Kennedy, Staci Wax, Rachel Minkoff, Ryan England, Ryan Menefee and Caroline Chow—used digital tire gauges to measure the air pressure in the tires of 81 cars that were parked in the East Campus Garage, the Doherty Apartments Lot and the Morewood Lot. Based on the assumption that the optimum air pressure for fuel efficiency was the maximum air pressure stated on the tires' sidewall, the four tires of each car were under-inflated by a total average of 20%. Only one of the 81 had the proper air pressure. (The suggested air pressure stated in owner's manuals is based on passenger comfort, not necessarily fuel efficiency.)

If you do the math to calculate the extra fuel cars consume due to under-inflated tires, consider the Environmental Protection Agency standard that a 1% loss of fuel efficiency occurs for every 2 PSI of air under the maximum level. Add to that the 2003 Department of Energy report that states that vehicles average 22.3 miles per gallon and 12,242 miles per year, and you find that each of the 81 cars burned 144 extra gallons of gas due to under-inflated tires. At $3 per gallon, each car owner is spending $432 for gas each year that they really don't need.

FOR USE BY PURGEN98 DEALERS ONLY Page 72 of 168 More than 3,000 individuals in the campus community applied for parking permits last year. Consequently, properly inflated tires would result in an annual savings of more than $1,296,000 for the campus community.

"After seeing the numbers I was really surprised to see just how much properly inflated tires make a difference," said Loviglio, a fifth-year scholar from Long Island, N.Y. "It really doesn't take that much to save a lot of money and pollute the air less."

Speaking of air pollution, 20.8 pounds of carbon dioxide are emitted into the Of the 81 cars checked, only one atmosphere for every one gallon of fuel consumed. Do the math again, and you'll find that had the proper air pressure in all each of those 81 cars emit an extra 1 1/2 tons of carbon dioxide annually. four tires.

Considering that three trees are needed to absorb 1 1/2 tons of carbon dioxide, more than 9,000 additional trees (22.5 acres) are needed to offset the extra greenhouse gases emitted from the more than 3,000 vehicles that park on campus. Without those additional trees, the extra CO2 is released into the atmosphere.

"This was an interesting exercise in that it demonstrated that saving the environment can actually save money and it raised awareness that what we do as individuals really does matter to the environment . . .even on a global scale," said Deborah Lange, executive director of the Steinbrenner Institute for Environmental Education and Research.

The study was sponsored by the Steinbrenner Institute with assistance from David Shiller (S'90), who along with David Molder (HSS'87) owns the E-House Company on Pittsburgh's Southside, a supplier of many environmentally friendly products.

For more on the Steinbrenner Institute, visit http://www.cmu.edu/environment.

FOR USE BY PURGEN98 DEALERS ONLY Page 73 of 168 CheckCheck YYourour TTireire PPressureressure Safety Facts • Properly inflated tires can save 30 psi 20 psi 5 cents a gallon in gas.

DANGER! • A well tended tire can last for Over loading 40,000 to 80,000 miles. results in tire damage.

• Under inflated tires can build up Gross vehicle weight = 6840 lbs. Gross vehicle weight = 6840 lbs.

heat, which could cause potentially Tire carrying = 6840 lbs. Tire carrying = 5610 lbs. capacity at 30 psi capacity at 20 psi fatal blowouts. Based on tire size P235/75R15 • Tire pressure is the single greatest These tires are 1230 cause of tire damage and failure. pounds OVERLOADED!

Maintenance Facts 100% = 32.0 psi • Have tires balanced and rotated 90% = 28.8 psi 80% = 25.6 psi every 5,000 to 8,000 miles. 70% = 22.4 psi 60% = 19.2 psi • Maintain adequate tread depth on 50% = 16.0 psi 40% = 12.8 psi tires, at least 1/16th inch. 30% = 9.6 psi 20% = 6.4 psi • Have vehicle alignment 10% = 3.2 psi checked often. 100% 10%

Environmental Facts • 5% under inflation increases fuel consumption 1%, and releases 1.5 million tons of carbon dioxide (CO2).

• Maintaining proper tire pressure generates less scrap tires per year.

70% looks like 100% When To Check Tire Pressure • Check tires when they are cold.

• Check tires routinely once a month.

• Check tires before long trips. Even 40% looks like 100%

Michigan Department of Transportation Gloria J. Jeff Jennifer M. Granholm Steven E. Chester Director Governor Director

FOR USE BY PURGEN98 DEALERS ONLY Page 74 of 168 Bridgestone/Firestone Commercial Truck Tires

ULTIMATE TRUCK TIRE AUTHORITY

another LOOK

The Tire Doctor Responds: Air may be free, but as stingy as some people are with it, you’d think it cost a fortune. In fact, as we’ll see, a simple, preventable problem like low air pressure costs many fleets real money in both tires and fuel.

Why are you always harping on proper inflation pressure?

Tires are called “pneumatic,” from the Greek word “pneuma,” meaning “air, wind or breath.” And there’s a reason for that.

What supports your cargo is pressurized air, NOT your tires. The tire is just the container – that holds the air – that supports the load.

But why so much fuss about exactly the right pressure?

As we mentioned in “By Popular Demand,” the right inflation pressure can minimize many types of irregular wear. And that means higher removal mileages and reduced tire handling costs.

In other words, tires last longer when properly inflated. Clearly, it's not the tire How much longer? that supports the load, but the pressureed air inside it. The Maintenance Council (TMC) reports that 10 percent underinflation will shorten tread life by 9 to 16 percent.

If we use an average tire price of $250, that underinflation costs you $25 per tire. And, because you’ll change tires more often, you’ll pay more in tire service fees, along with downtime.

And how many drivers and maintenance people, if they had a target inflation pressure of 100 psi, would consider 90 psi (10 percent underinflated) “close enough”?

What if the underinflation is worse than that?

TMC suggests that each 10 percent results in a similar loss in tread life.

So 20 percent underinflation could cost you $50 per tire. And if underinflation exceeds 10 percent, you may have bigger problems. Like flats and emergency road service calls that can cost anywhere file:///C|/Documents and Settings/Robin/Desktop/Bridgestone High Costs of Low air pressure.htm (1 of 3)12/11/2005 11:01:23 AM FOR USE BY PURGEN98 DEALERS ONLY Page 75 of 168 Bridgestone/Firestone Commercial Truck Tires

from $100 to $1,000.

Both TMC and the Rubber Manufacturers’ Association (RMA) recommend that any tire found to be 20 percent or more underinflated should be immediately removed from service, demounted and inspected for damage. What about duals?

If the tires don’t match in diameter, the smaller tire is dragged along by the larger (see “By Popular Demand,”).

This can result in extremely rapid and irregular wear on the smaller tire. If duals differ in inflation, their diameters can differ enough to cause this kind of problem.

Are wear and fuel economy the only losses?

They’re just the beginning. Imagine bending the sidewall of a tire with your hands 500 times a minute. A truck tire goes through a full revolution, flexing all the way around, about 500 times per mile. At 60 miles per hour – a mile a minute, that’s 500 times a minute. Tire engineers call this flexing “deflection.” With underinflation, there’s even more deflection, consuming more energy and using more fuel.

How much more?

Underinflation by 10 psi will probably cost you about 0.5 percent in miles per gallon. (See “Technically Speaking,”) If you currently get 6 mpg, it would drop to 5.97 mpg. At 100,000 miles per year, you’d use an extra 84 gallons of diesel, or about $84 per truck, just in wasted fuel.

Are there any other losses as a result of underinflation?

Unfortunately, lots of them.

Remember what we said about “deflection”? Excessive deflection weakens steel cords excessively. And it’s accepted as a fact in the tire industry that under-inflation is a major contributor to premature tire removals.

But even if things don’t go that far, flexing can generate excessive heat, the enemy of tire casings. Just as time ages people, heat ages tires. And, if you’ve been accustomed to getting 2 retreads from each casing, you may discover that your average has dropped to 1.5.

What would that cost?

If your casings are worth $60-$80, instead of getting a useful retread, you could lose that much, plus the $3-$7 disposal fee required by most states.

Why don’t you just make tires that don’t leak?

Because the gas molecules in air are too small. Eventually they can diffuse through the rubber of a tire, and escape into the atmosphere. This doesn’t happen quickly, but it means you can lose up to 2 psi per month through diffusion alone.

What can we do to prevent pressure losses?

Check pressure regularly. Use a good gauge, and calibrate it often. (In a future issue of Real Answers magazine, we’ll show you how to build your own master gauge.)

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To keep air in, keep wheels clean and properly lubricated. And, make sure valve stems and cores are in good condition.

Finally, quality metal valve caps are a must. Caps are the primary seal against valve leaks, and also keep dirt and water out of the mechanism.

Why is that important?

A valve core is a mechanical device that must seal at very high pressures. If a tiny bit of dirt gets in, it can prevent proper sealing.

Likewise, just as water can freeze and crack concrete, water can freeze inside valve stems, disrupting the seal. Check calibration of pressure guages But it does cost something to check air pressure, doesn’t it? regularly, using a master guage.

Certainly. But according to TMC data, it only takes about 20 minutes to check and adjust inflation pressure on an 18-wheeler. If you do it every week, chances are you’ll have very few problems with underinflated tires.

That means increased uptime, better fuel efficiency, longer tread life and improved retreadability – all of which can put real money into your pocket.

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ULTIMATE TRUCK TIRE AUTHORITY

The Shocking Truth! Where does the air go?

Recently, we did a survey of inflation pressure on the Why can’t we just put air in our tires once, then

dual tire assemblies of emergency medical service forget about them?

vehicles. Here's what we found: How does the air get out?

About 39 percent of the tires couldn’t be checked at all, Well, air can escape from tires in lots of ways. Clearly,

because valve stems were inaccessible. We don’t know if there could be a puncture, a nail that’s causing “a slow

inflation was correct or not. Worse, even if one of these tires leak.” But there are lots of other ways air can escape. needed air, there was no way to add any. Today’s tires are tubeless, which means that the tire

Some vehicles had extension hoses, so at least we could itself has to seal directly against the wheel. Improper or

check them. Nevertheless, results were pretty grim. inadequate lubrication or a damaged wheel can cause air

to escape at the interface between tire and wheel. Nearly 2/3rds of those tires were underinflated by at least 20 Damaged, defective or contaminated valve stems, as psi. That’s dangerously low. Since the manufacturer’s we’ve seen, can leak as well. specification is 80 psi, these tires were 25 percent

underinflated. But even if all those things were perfect, tires would still

lose air. Depending on size, they can lose between 1 and The tire industry considers any tire that's been run on the 2 psi per month. road 20 percent or more underinflated to be “run flat.”

Running flat can result in very serious damage to the tire that How is it getting out? Well, just as gases can permeate

can cause it to fail catastrophically – and without warning. the membranes of the body, air can and does permeate

the rubber in tires. Air molecules literally find their way Of these underinflated tires, 2/3rds were the inside tire of the out of the tire – slowly – resulting in a gradual loss of air dual assembly, which is nearly impossible to see. Only about pressure. 13 percent – roughly one in eight of the tires we checked –

had the correct inflation pressure. That's why you need to check your tires frequently, even

if there’s no obvious damage to them.

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Just as gases can permeate membranes in the human body, air can permeate the The tire industry considers any tire that’s rubber in tires, resulting in a loss of air been run on the road 20% or more pressure of between 1 and 2 psi per underinflated to be “run flat.” month, depending on the size of the tire.

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Proper Inflation

SAFETY WARNING: Serious injury may result from tire underinflation/overloading. Follow Owner's Manual and tire placard in vehicle.

MAINTAIN PROPER INFLATION PRESSURE IN YOUR TIRES.

Proper inflation pressure is necessary for optimum tire performance, safety and best fuel economy. To maintain proper inflation pressure, frequently check tires (when they are cool) with an accurate tire pressure gauge. For example, it is difficult to tell just by looking at radial tires whether they are under inflated.

• Evidence of air loss or repeated under inflation requires tire removal and expert inspection.

Always maintain inflation pressure at the level recommended by the vehicle manufacturer as shown on the vehicle placard or in the Owner's Manual. Higher inflation pressure increases stiffness which may deteriorate ride and generate unwanted vibration.

Tire footprint and traction are reduced when van, pickup or RV tires are over inflated for the loads carried. In particular, tires with aggressive tread patterns may contribute to oversteer or "roadwalk" if inflated beyond the inflation pressure specified in the Owner's Manual and vehicle placard for standard or customary loads. Over inflation also increases the chances of bruise damage.

Under inflation is the most common cause of failures in any kind of tire and may result in severe cracking, component separation or "blowout," with unexpected loss of vehicle control and accident. Under inflation increases sidewall flexing and rolling resistance resulting in heat and mechanical damage.

Furthermore, when operating a vehicle equipped with radial tires, it is difficult to notice when a tire has gone flat or near flat since the "feel" of the vehicle does not change significantly. http://www.dunloptires.com/care/proper_inflation.html

FOR USE BY PURGEN98 DEALERS ONLY Page 80 of 168

A tire is a pneumatic system, which supports a vehicle's load. It does this by using a compressed gas (usually air) inside to create tension in the carcass plies. It is important to realize that a tire carcass has a high-tension strength, but has little or no compression strength. It is the air pressure that creates tension in the carcass and allows the tire to function as a load-carrying device. That's why inflation is so important. In an inflated, but unloaded tire, the cords pull equally on the bead wire all around the tire. When a tire is loaded, the tension in the cords between the rim and the ground is balanced or relieved. The tension in other cords is not changed. Therefore, the cords opposite the ground pull upwards on the bead. This is the mechanism that transmits the pressure from the ground to the rim.

In addition, a tire must transmit handling (acceleration, braking, cornering) to the road. Cornering forces are transmitted to the rim in a similar manner to load. Acceleration and braking forces rely on the friction between the rim and the bead. Inflation pressure also supplies the clamping force, which creates friction.

A tire also acts as a spring between the rim and the road. This spring characteristic is very important to the vehicle's ride.

Too high an inflation pressure causes the tire to transmit shock loads to the suspension and reduces a tire's ability to withstand road impacts.

Too low an inflation pressure reduces a tire's ability to support the vehicle's load and transmit cornering, braking and acceleration forces.

Finding the optimum inflation pressure requires extensive engineering efforts on the part of tire and vehicle manufacturers.

http://www.dunloptires.com/care/proper_inflation.html

FOR USE BY PURGEN98 DEALERS ONLY Page 81 of 168 Under-inflation can cause many tire-related problems. Because a tire's load capacity is largely determined by its inflation pressure, under-inflation results in an overloaded tire. An under-inflated tire operates at high deflection, resulting in decreased fuel economy, sluggish handling and may result in excessive mechanical flexing and heat buildup leading to catastrophic tire failure.

Correct inflation is especially significant to the endurance and performance of radial performance tires. For example, because of a performance radial's aspect ratio and design, it may not be possible to look at a radial tire and actually see under-inflation of 5 psi. However, under-inflation of 5 psi can reduce a performance tire's tread life by 25%. A typical tire may also lose 1 to 2 psi a month, if not checked and adjusted.

Temperature Effects: Air pressure is affected by temperature. The air under pressure in a tire is no exception. Typically, an inflation pressure can change by 1 psi for every 10 degrees Fahrenheit of temperature change. Higher temperature means increased pressure.

For example, if a tire is inflated to 35 psi on an 80-degree July day, it could have an inflation pressure of 23 psi on a 20-degree day 6 months later in January. This represents a normal loss of 6 psi over the six months and an additional loss of 6 psi due to the 60- degree temperature change. At 23 psi, this tire is severely under-inflated.

SAFETY Note: For safety and vehicle performance, Dunlop recommends that tire inflation pressure be checked at least once each week and as often as possible when tires are cold (ambient air temperature and if the vehicle has not been driven for several hours.) Repeat or excessive inflation loss (more than 2 psi); visible damage such as knots, bulges, punctures, cuts, cracks, irregular wear; experiencing impacts, vibration or pulling; all require removal, expert inspection of tire and rim to determine reparability, or the need for replacement. Damaged tires may fail suddenly or burst upon re-inflation, resulting in serious injury

http://www.dunloptires.com/care/proper_inflation.html

FOR USE BY PURGEN98 DEALERS ONLY Page 82 of 168 Dunlop Claims U.S. Drivers may be Wasting More than $10Billion at Gas Pumps

AKRON, Ohio – U.S. motorists may be wasting more than $10.3 billion at the gas pump annually, because they spend too little time at the air pump, according to Dunlop tire officials. According to statistics from Dunlop engineering, tires under-inflated by only 4 to 5 pounds per square inch cause a vehicle to gulp – and waste – an extra 10 percent of fuel. And because studies show that about 28 percent of tires are under-inflated, that’s $10,344,111,911 in wasted fuel.

In addition, due to this waste, motorists must visit gas pumps an additional 328 million times. Dunlop data is based on cars that travel 20,000 miles per year, require 15 gallons per fill-up, average 20 miles per gallon for the U.S. fleet of vehicles and pay record $2.10-per-gallon gas prices.

Since tires account for 4 to 7 percent of a car’s fuel consumption, keeping tires properly inflated has a huge effect on America’s pocketbooks, according to Bill Egan, chief engineer of advanced product design for The Goodyear Tire & Rubber Company. Ten years ago, the U.S. Energy Department said under-inflated tires wasted 4 million gallons of gasoline daily – or nearly 1.5 billion gallons annually – in America. Egan calls the country’s rising gasoline bills “tire-fuelish,” a money-wasting malady that could be cured by spending five minutes a month with vehicle tires at the air pump.

Motorists must check tire inflation monthly or before a long trip. Tires should be inflated to the vehicle manufacturer’s recommendation printed on the vehicle’s door placard or in the owner’s manual.

“An under-inflated tire consumes more energy and increases rolling resistance, which robs the vehicle of fuel efficiency,” Egan said. “Tire-fuelishness is a double-edged sword. It wastes gasoline, whic causes demand to increase.”

Some organizations are calling for more fuel-efficient tires to help save fuel costs, but Egan said these proposals are merely stop-gap measures. “As long as motorists continue to neglect their tires, America will continue to waste gasoline and money at the pumps."

“Even the most fuel-stingy Dunlop tires on the road would be ineffective without the correct inflation pressures,” he added.

Drivers in Hawaii with under-inflated tires have the most to lose – with gas prices averaging $2.43 per gallon. New Jersey motorists lose the least, at $1.94 a gallon

http://www.womanmotorist.com/index.php/news/main/3760/event=view

FOR USE BY PURGEN98 DEALERS ONLY Page 83 of 168

Keep Your Engine Properly Tuned

Fixing a car that is noticeably out of tune or has failed an emissions test can impove its gas mileage by an average of 4 percent, though results vary based on the kind of repair and how well it is done.

Fixing a serious maintenance problem, such as a faulty oxygen sensor, can improve your mileage by as much as 40 percent.

Fuel Economy Benefit: 4% Equivalent Gasoline Savings: $0.13/gallon

Check & Replace Air Filters Regularly Replacing a clogged air filter can improve your car's gas mileage by as much as 10 percent. Your car's air filter keeps impurities from damaging the inside of your engine. Not only will replacing a dirty air filter save gas, it will protect your engine. Fuel Economy Benefit: up to 10% Equivalent Gasoline Savings: up to $0.31/gallon

Keep Tires Properly Inflated You can improve your gas mileage by around 3.3 percent by keeping your tires inflated to the proper pressure. Under-inflated tires can lower gas mileage by 0.4 percent for every 1 psi drop in pressure of all four tires. Properly inflated tires are safer and last longer.

Fuel Economy Benefit: up to 3% Equivalent Gasoline Savings: up to $0.09/gallon

FOR USE BY PURGEN98 DEALERS ONLY Page 84 of 168 Gasoline Savings Information Guide

Fact Source

Americans use about 375 million gallons of gasoline per day. www.eia.doe.gov Energy Information Administration That equals 136,875,000,000 gallons per year. Official Energy Statistics from the U.S. Government

220 million vehicles in the U.S. drive 11,600 miles per year. www.eia.doe.gov Energy Information Administration Conclusion

If 85% of the 220 million vehicles on the road today improved their gas mileage by 3.3%, the U.S. would save 3.8 billion gallons of gas per year.

FOR USE BY PURGEN98 DEALERS ONLY Page 85 of 168 Inflation S ECTION F IVE

A tire requires proper air pressure on load and service conditions. Most data each axle position. That would be ideal, to adequately carry the load placed on contained in this book is taken from tables but impractical for many linehaul fleets. it. The “container volume,” material published by the Tire & Rim Association Equal inflation pressure properties and inflation pressure determine (T&RA). Its members, U.S.-based tire, To compromise, determine the proper the load carrying capacity of the tire. rim and wheel manufacturers, set the inflation pressure for each tire on the Figure 5.1 Your tires provide traction for technical standards for manufacturing vehicle and use the highest pressure. braking, accelerating and turning and those products in this country. Remember that overinflation is preferred must carry out these tasks for many Using the tables is quite simple. First, to underinflation. That makes the miles. Without proper inflation pressure, determine the maximum load that your compromise acceptable. tires cannot carry out these tasks as they tire is likely to encounter. Then, for your Also consider operating speeds. were designed to do. tire size/ply rating, find the load in the Vehicles operated at less than highway But what is the proper inflation for table that is close to but slightly more speeds can carry greater loads, as shown your tires? A simple answer would be than the maximum anticipated load. The in Table 3. great, but not practical. inflation pressure at the top of this column Using load/inflation tables can help is your minimum pressure for the load. Loads determine inflation you get the most from your current tires. All tire manufacturers offer load/ Duals vs. singles It can also help you choose future tire inflation tables that can be used to Note that loads are shown for single sizes based on your vehicles’ needs and determine the proper inflation pressure and dual applications. When you run their service conditions. at various loads. duals, the allowable load at any given Always check inflation pressures when Load/inflation tables for Goodyear inflation pressure will be less than with tires are cold. Never bleed air from hot commercial tires are published on the singles. That’s to minimize overloading tires to relieve normal pressure build-up. Web site www.godyear.com/truck and in the when one tire in a dual assembly is The normal increase in pressure due to Engineering Data Book for Over-the-Road underinflated and to compensate for service conditions will be 10 to 15 psi, Truck Tires. This book, available at your road crown. and this is allowable in a radial truck tire. Goodyear Commercial Truck Tire Center, Position is another consideration. Steer, It is particularly important to keep and is updated periodically with the latest drive and trailer tires may carry different moisture from the inside of any tires and sizes and types of commercial truck tires. loads, with steer tires normally handling we strongly encourage proper selection Section “L” in this data book provides the heaviest because they run as singles. of compressor equipment, air-line routing, the information you’ll need to determine To optimize tire performance, you may and the use of air dryers to avoid moisture the proper inflation for your tires based require different inflation pressures in in high pressure air used for inflation.

LOAD Container Volume

Figure 5.1

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A tire’s cold inflation pressure will Since this difference is small, the effect The inflation pressure reading at change with altitude and temperature. of altitude change on tire inflation, in 0 degree F might happen when the truck The air pressure gauge reads the difference general, is not considered to be significant. is parked on a cold winter night. It will between the tire’s contained air pressure Ambient temperature effects on a increase rapidly, though, once the truck and atmospheric pressure. Atmospheric tire’s cold inflation pressure, on the other begins to run and the tires warm up. pressure changes 0.48 psi for every 1000 hand, is significant. Using as an example At the other extreme of ambient feet change in altitude. Assuming constant a tire with an initial inflation pressure temperatures, for example during the temperature and internal tire volume, of 100 psi at 60 degree F ambient summer, it is common to find tire inflation if a tire pressure gauge reads 100 psi at temperature, for each 10 degree F change pressures in the 115 to 120 psi range. sea level, for every 1000 feet increase in temperature, there is about a 2 psi We always caution operators not to in altitude, the gauge will read 0.5 psi change in the tire’s inflation pressure, bleed air pressure down on cold tires higher inflation pressure, see Figure 5.2. see Figure 5.3. when they are at these higher ambient temperature conditions. Always inflate 105 tires cold to the required pressure no matter whaat the ambient temperature is.

104 UNDERINFLATION Underinflation can have detrimental 103 effects on the performance of your tires and vehicles. Increased tire wear rate, irregular treadwear, reduced casing 102 durability and lower fuel economy are

Inflation Pressure (psi) some of the unnecessary costs incurred

101 from tires not properly inflated. Running on underinflated tires costs you in lost tread life and higher fuel 100 consumption. Tests conducted by Goodyear have shown that just 15 0 1000 2000 3000 4000 5000 Altitude (feet) percent underinflation of steer, drive and trailer tires results in about an 8 Figure 5.2 percent drop in expected tread mileage and a 2.5 percent decrease in miles per gallon, Figure 5.4. 120 100

110 90

100 80 Inflation Pressure (psi) 90 70 Expected Mileage (percent)

80 60 0 20 40 60 80 100 120 140 0102030 Ambient Temperature (deg F) Under Inflation (percent)

Figure 5.3 Figure 5.4 40 FOR USE BY PURGEN98 DEALERS ONLY Page 87 of 168

NHTSA 46-01 Wednesday, August 29, 2001 Contact: Elly Martin Telephone: (202) 366-9550

Many U.S. Passenger Vehicles Are Driven on Under-inflated Tires, NHTSA Research Survey Shows

U.S. Transportation Secretary Mineta Urges Motorists To Check Tire Pressure Before Labor Day Travel

Prompted by the Administration’s emphasis on transportation safety and a new survey showing that many tires on passenger vehicles are under-inflated, U.S. Transportation Secretary Norman Y. Mineta today urged motorists to check their tire pressure and inflate them properly before setting out on trips for the Labor Day weekend.

“It is vitally important to safety to carefully monitor tire pressure on a regular basis, and I urge motorists to check their tires before setting out on Labor Day trips,” Secretary Mineta said. “Driving with substantially under-inflated tires can lead to crashes and tragedy, in addition to reducing fuel efficiency and shortening tire life.”

Safety is the Bush administration’s highest priority for transportation.

Fully 27 percent of passenger cars on U.S. roadways are driven with one or more substantially under-inflated tires, according to a major survey conducted by the U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA).

Moreover, 32 percent of light trucks (including sport utility vehicles, vans and pickup trucks) are driven with one or more substantially under-inflated tires, according to the first study of its kind to be conducted by the government in two decades.

A radial tire can lose much of its air pressure and still appear to be fully inflated. To help vehicle owners better monitor the air pressure in their tires, NHTSA last month proposed a new federal motor vehicle safety standard that would require the installation of tire pressure monitoring systems in new passenger cars and light trucks. The proposed requirement would also cover buses and multipurpose vehicles with a gross vehicle weight rating of 10,000 pounds or less. The new systems would warn the driver when a vehicle has a significantly under-inflated tire.

FOR USE BY PURGEN98 DEALERS ONLY Page 88 of 168

For purposes of the survey, a tire was considered under-inflated at 8 psi (pounds per square inch) or more below the vehicle manufacturer’s recommended inflation pressure. This is 25 percent of a common recommended cold inflation pressure of 32 psi.

Operating a vehicle with substantially under-inflated tires can result in a premature tire failure, such as instances of tread separation and blowouts, with the potential for a loss of control of the vehicle. Under-inflated tires also shorten tire life and increase fuel consumption.

Tires should be inflated in accord with the vehicle manufacturer’s recommendations. These can be found in the owner’s manual or on a placard usually located on the driver’s door jamb. Motorists should not rely on visual tire inspections to determine whether a tire is properly inflated but should use a tire pressure gauge to do so. Tire pressure should be checked at least once a month and before a long trip.

The study was based on information gathered by 67 data collectors who measured the inflation pressure of tires on 11,530 passenger vehicles during a 14-day period in February 2001. The information was collected with the cooperation of motorists who visited service stations for refueling at 300 sites in urban, suburban and rural settings located throughout the country.

Key findings of the NHTSA study include these estimates:

• Six percent of light trucks (sport utility vehicles, vans and pickup trucks) are driven with all four of their tires under-inflated by 8 or more psi, compared with 3 percent of passenger cars. • Ten percent of light trucks are driven with three or more tires underinflated by 8 or more psi, compared with 6 percent of passenger cars. • Twenty percent of light trucks have two or more tires under-inflated by 8 or more psi, compared with 13 percent of passenger cars.

The survey results also indicate that older vehicles are notably more likely to be operated with substantially under-inflated tires than are newer vehicles.

NHTSA estimates that 49 to 79 deaths and 6,585 to 10,635 injuries could be prevented annually if all vehicles were equipped with tire pressure monitoring systems. In addition, vehicle owners would benefit from better vehicle handling, increased tire life and better fuel economy.

NHTSA’s National Center for Statistics and Analysis, which conducted the survey, plans to complete a detailed report on its tire pressure study by the end of 2001.

The newly released NHTSA statistics are contained in a research note on the agency’s Website at: www.nhtsa.dot.gov/people/ncsa.

FOR USE BY PURGEN98 DEALERS ONLY Page 89 of 168 FOR USE BY PURGEN98 DEALERS ONLY Page 90 of 168 Rubber Association - Proper Tire Inflation

• Tire Vehicle Placard Proper Inflation • Benefits

• Proper Inflation • Pressure Factors Effects of Under Inflation on Tire Wear and Fuel Use • Monitoring Systems

Proper tire pressure is critical for safe driving and fuel efficiency, but many passenger and light truck vehicles operate with under or over-inflated tires. Ninety-five per cent (95%) of a vehicle's weight is supported by the tire air pressure, with the tire supporting just 5%, making inflation a critical part of a tire's ability to perform. Tire inflation also has a strong impact on tread life.

Relying on a sight inspection alone is not an accurate way to measure tire pressure. Tires may be significantly under or over-inflated, yet you may not be able to tell just by looking at them.

The only accurate way to know if your tires need to be inflated is by measuring their pressure with a reliable tire gauge. Tire gauges are available at most automotive supply and hardware stores.

● Correct Tire Pressure Correct tire pressure varies from vehicle to vehicle and wheel to wheel. In fact, the recommended pressure for personal vehicles ranges from 20 to over 50 psi.

The correct tire pressure for your vehicle is listed on the information placard. This placard is normally located on the edge of one of the doors, the inside post of one of vehicle's doors or inside the glove compartment, trunk, or fuel door. Your owner's manual should include the correct tire pressure or direct you to the placard's location on your vehicle.

The pressure listed on the tire sidewall is the maximum tire pressure - or the tire pressure that is required to carry the maximum load of the tire. It is not the manufacturer's recommended tire pressure, which is a common misperception.

In addition to keeping your tires properly inflated, follow these tire maintenance guidelines.

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● Under-inflation Under-inflation is the leading cause of tire failure. Twenty-three per cent (23%) of vehicles have at least one tire under-inflated by more than 20%. Under-inflated tires on your vehicle lead to poor or delayed braking, steering and acceleration. Under-inflated tires may squeal when stopping or cornering even at moderate speeds, particularly on warm pavement.

The Effects of Under Inflation on Tire Wear and Fuel Use

Percentage of Under Percentage Wear Fuel Use Inflation Increase Increase

10% 5% 2%

20% 16% 4%

30% 33% 6%

40% 57% 8%

50% 78% 10%

Operating a vehicle with just one tire under-inflated by 20% (8psi) can reduce the life of the tire by 15,000 km and can increase the vehicle's fuel consumption by 4%. Without enough air, the sides of a tire bend and flex too much. This builds up heat, which can cause serious damage and leads to sudden tire failure. It will also increase rolling resistance, which reduces tread life and increases fuel consumption.

● Over-inflation Over-inflation can be a problem too. An over-inflated tire rides on just the centre portion of the tread. The smaller contact area means reduced grip on the road, leading to a harsh ride, handling issues (such as steering and stopping problems) and increased wear on tires and suspension components. Seventeen per cent (17%) of vehicles in Canada have at least one tire that is over-inflated by 20%.

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Tire Safety Fact Sheet

Each month, three out of four drivers wash their cars while only one out of seven correctly checks their tire pressure.

Motorists rank checking tire pressure as the second most important regular vehicle safety action, but more than three times as many drivers believe regular oil changes are most important to the safe operation of their vehicles.

Only 15 percent of drivers properly check their tire inflation pressure. To properly check tire inflation pressure: o Check tire inflation pressure at least once a month o Use the correct inflation pressure recommended by the vehicle manufacturer, not the pressure listed on the tire sidewall o Check tires when they are cold or haven’t been driven for at least three hours

More than half of drivers -- 55 percent -- wrongly believe that the correct inflation pressure is printed on the tire sidewall.

30 percent of drivers wrongly believe that the best time to check their tires is when they are warm after being driven for at least a few miles.

Nearly 1/3 of drivers wrongly believe that if they are taking a trip with a fully loaded vehicle that they are better off if their tires are a little bit underinflated.

Two out of three drivers don’t know how to tell if their tires are bald.

71 percent of drivers do not check their tire pressure in their spare tire.

40 percent of drivers have not rotated their tires within the recommended interval of at least 8,000 miles.

The RMA sponsored survey was conducted by FrederickPolls to 2,200 drivers nationwide from January 29-February 11, 2004 and has a margin of error of 2%

FOR USE BY PURGEN98 DEALERS ONLY Page 93 of 168 Automatic tire inflation systems can save tire maintenance costs and improve fuel economy by nearly 1%, saving 100 gallons of fuel and eliminating one metric ton of greenhouse gas emissions per year. Properly inflated tires also wear longer and have fewer punctures.

What is the challenge? When not properly inflated, tires flex more under What is the solution? load, producing heat and increasing rolling Automatic tire inflation (ATI) systems monitor and resistance, which wastes fuel. Truck tires inflated ten continually adjust the level of pressurized air in tires, pounds per square inch (psi) below recommended air maintaining proper tire inflation automatically, even pressure levels can reduce truck fuel economy from while the truck is moving. One ATI system uses the 0.5 percent to one percent. Heat and stress from vehicle’s own air-brake compressor to supply air to all improper inflation soften and deflect tire components, the tires. Another system uses self-contained causing faster and more uneven wear, which compressors mounted on each hub that are powered shortens the life of the tire. Under inflated tires have by the rolling motion of the wheels. Once an ATI more frequent punctures, increasing the risk of tire system is installed, it should not require any special failures that could lead to costly road service and loss attention from the driver. of revenue. The results are in . . . Despite these costs, a recent survey of combination ATI systems can extend tire life by eight percent or trucks found that less than half the tires surveyed more. The systems eliminate the need to check tire were within five percent of the recommended inflation pressure manually, saving time and labor while pressure. Fleets may find it difficult to keep tires ensuring consistent and proper tire inflation. Installing properly inflated since truck tires can lose up to 2 psi an ATI system on a truck’s drive axles and trailer each month, even if the rim seal and valve stems are costs up to $900, but can save over $200 annually in tight. This is because air molecules can permeate tire maintenance costs. For a typical long-haul through tires. Temperature and load also affect tire combination truck, annual fuel savings could reach pressure. For these reasons, tire manufacturers 100 gallons, saving $170 in fuel costs and eliminating recommend checking tire pressure each week and one metric ton of greenhouse gas emissions. The establishing a tire maintenance program. cost of installing an ATI system in a line-haul truck is generally recouped in just over two years through Even a good tire maintenance program may fall short fuel and maintenance cost savings. Truck fleets may of its aims. In part, this is because trailer tires have realize additional savings from reducing the risk of more impact on truck fuel economy than tractor tires, expensive tire failure caused by under inflation. yet trailers are interchangeable and thus harder to monitor. Since the bulk of the load is carried in the trailer, a 10-psi under inflation in a trailer tire may Next steps have nearly twice the impact on truck fuel economy Line-haul carriers that find it too difficult or expensive as the same amount of under inflation in a drive tire. to monitor tire pressure on a regular basis should Despite the importance of keeping trailer tires consider installing automatic tire pressure inflation properly inflated, a fleet may not be able to inspect its systems on drive and trailer tires. ATIs can be readily trailers regularly. A trailer may be gone from the retrofitted onto existing trucks and trailers. Interested service yard for extended periods of time while on the fleets can check with ATI manufacturers and truck road, at a customer’s facility or at drop-off location and tire dealers for more information. Fleets may also waiting for a back haul. A fleet may not even own the contact tire manufacturers or their state or national trailers it hauls, but pick them up from a shipper or trucking associations for more information about the third party. These circumstances can place much of benefits of proper tire inflation. the responsibility for checking tire pressure onto drivers. However, one industry survey indicates only eight percent of truck drivers check tire pressure with a tire gauge before each trip.

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www.tireindustry.org

For Immediate Release Contact: Roy Littlefield June 7, 2005 301-430-7280

TIA Joins Lawsuit Against NHTSA on TPMS Rule

Bowie, MD – (June 7, 2005) The Tire Industry Association (TIA) announced today that they have joined with Goodyear Tire & Rubber Company, Bridgestone Firestone North American Tire, Cooper Tire & Rubber Co., Pirelli Tire and Public Citizen in a lawsuit against the National Highway Traffic Safety Administration’s (NHTSA) final rule on Tire Pressure Monitoring Systems (TPMS). The suit was filed late yesterday in the U.S. Court of Appeals for the District of Columbia.

“As TIA stated in our comments and our Petition for Reconsideration to NHTSA, we believe this TPMS rule is fatally flawed,” said Roy Littlefield, Executive Vice President of TIA. “Congress charged NHTSA with creating a rule that would keep the motoring public safe. This rule does not do that which is why we have joined in this lawsuit. This could be the first time in the history of rule-making that the industries impacted by a proposed regulation do not think that the proposal is stringent enough.”

TIA has consistently challenged NHTSA’s TPMS trigger threshold of 25 percent below the recommended cold inflation pressure as too high. “The 25 percent threshold set by this final rule wouldn’t have prevented the Ford/Firestone mess of 2000 that began this whole regulatory process,” said Dick Gust, President of TIA. “We are afraid that this rule, if it is allowed to stand, will make consumers more apathetic to their tires and our tire retailers, manufacturers and technicians more vulnerable to lawsuits in the future.”

“TPMS systems cannot take the place of regular maintenance on tires, “said Littlefield. “TIA and the other petitioners feel that safety is the priority of this regulation, and that NHTSA missed the mark.”

A copy of the lawsuit is available at http://www.citizen.org/documents/Petition_for_Review.pdf.

# # #

TIA is an international association representing all segments of the tire industry, including those that manufacture, repair, recycle, sell, service or use new or retreaded tires, and also those suppliers or individuals who furnish equipment, material or services to the industry. The Tire Industry Association (TIA) has a history that spans more than 80 years and includes several name changes. Originally known as the National Tire Dealers & Retreaders Association (NTDRA), the organization gave birth over the years to the American Retreaders Association (ARA) and the Tire Association of North America (TANA). ARA changed its name to the International Tire & Rubber Association (ITRA) and merged with TANA in 2002 to form the current Tire Industry Association (TIA), which now represents every interest in the tire industry.

Maryland Office: 1532 Pointer Ridge Place 800.876.8372 Suite G 301.430.7280 Bowie, Maryland 301.430.7283 f 20716-1883

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V. Summary of Preliminary Determination About the Final Rule

In this section, NHTSA summarizes its preliminary determination about the final rule that was submitted to OMB in December 2001.

A. Alternative Long-Term Requirements Analyzed in Making Preliminary Determination

For purposes of the preliminary determination, the agency analyzed three alternatives. The first alternative (four tires, 20 percent) would have required a vehicle's TPMS to warn the driver when the pressure in any single tire or in each tire in any combination of tires, up to a total of four tires, fell to 20 percent or more below the placard pressure, or a minimum level of pressure specified in the standard, whichever pressure was higher. The second alternative (three tires, 25 percent) would have required a vehicle's TPMS to warn the driver when the pressure in any single tire or in each tire in any combination of tires, up to a total of three tires, fell to 25 percent or more below the placard pressure, or a minimum level of pressure specified in the standard, whichever pressure was higher. The third alternative (four tires, 25 percent) combined aspects of the first two alternatives. It would have required a vehicle's TPMS to warn the driver when the pressure in any single tire or in each tire in any combination of tires, up to a total of four tires, fell to 25 percent or more below the placard pressure, or a minimum level of pressure specified in the standard, whichever pressure was higher. The minimum levels of pressure specified in the standard would have been the same for all three alternatives.

The agency estimated that the four-tire, 20 percent alternative would have prevented from 141 to 145 fatalities and prevented or reduced in severity from 10,271 to 10,611 injuries per year. (30) The agency estimated that the average net cost of this alternative would have been from $76.77 to $77.53 per vehicle. (31) Since approximately 16 million vehicles are produced for sale in the United States each year, the total annual net cost of this alternative would have been from $1.228 billion to $1.241 billion. The net cost per equivalent life saved would have been from $5.1 million to $5.3 million.

The agency estimated that the three-tire, 25 percent alternative would have prevented 110 fatalities and prevented or reduced in severity 7,526 injuries per year. The agency estimated that the average net cost would have been $63.64 per vehicle, and the total annual net cost would have been $1.018 billion. The net cost per equivalent life saved would have been $5.8 million.

The agency estimated that the four-tire, 25 percent alternative would have prevented 124 fatalities and prevented or reduced in severity 8,722 injuries per year. The agency estimated that the average net cost would have been $53.87 per vehicle, and the total annual net cost would have been $862 million. The net cost per equivalent life saved would have been $4.3 million.

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The agency noted that the vehicle costs of these alternatives could be reduced in the future as manufacturers learned how to produce TPMSs more efficiently. Moreover, maintenance costs could be significantly reduced in the future if manufacturers could mass produce a direct TPMS that did not require the pressure sensors to be replaced when the batteries are depleted. (32)

NHTSA considered these three alternatives because the agency believed that TPMSs that complied with these alternatives would warn drivers of significantly under-inflated tires in a wide variety of reasonably foreseeable circumstances, including when more than one tire was significantly under-inflated. The agency also believed that improved indirect TPMSs could be developed to meet the requirements of the three-tire, 25 percent alternative and hybrid TPMSs could be developed to meet the three-tire, 25 percent and four-tire, 25 percent alternatives. Thus, the agency believed that these alternatives would provide an effective warning while striking a reasonable balance between encouraging further improvements in TPMS technology and stringency of the performance requirements and striking a reasonable balance between safety benefits and costs.

B. Phase-In and Long-Term Requirements

To facilitate compliance, the preliminary determination specified a four-year phase-in schedule, (33) During the phase-in, i.e., between November 1, 2003 and October 31, 2006, it would have allowed compliance with either of two options: a four-tire, 25 percent option or a one-tire, 30 percent option. Under the first option, a vehicle's TPMS would have had to warn the driver when the pressure in one or more of the vehicle's tires, up to a total of four tires, was 25 percent or more below the placard pressure, or a minimum level of pressure specified in the standard, whichever pressure was higher. Under the second option, a vehicle's TPMS would have had to warn the driver when the pressure in any one of the vehicle's tires was 30 percent or more below the placard pressure, or a minimum level of pressure specified in the standard, whichever pressure was higher. The minimum levels of pressure specified in the standard were the same for both compliance options.

Under both options, the preliminary determination would have required the low tire pressure warning telltale to remain illuminated as long as any one of the vehicle's tires remained significantly under-inflated, and the key locking system was in the ""On"" (""Run"") position. The telltale could have been deactivated automatically only when all of the vehicle's tires ceased to be significantly under-inflated, or manually in accordance with the vehicle manufacturer's instructions.

The preliminary determination would have required each TPMS to be compatible with all replacement or optional tires (but not rims) of the size(s) recommended for use on the vehicle by the vehicle manufacturer. It would also have required that the telltale perform a bulb-check at vehicle start-up. It specified written instructions explaining the purpose of the low tire pressure file:///C|/DocumentsFOR andUSE Settings/Robin/Desktop/NHTSA BY PURGEN98 DEALERS TPMS ONLY Summary.htm (2 of 4)12/11/2005 11:41:19 AM Page 97 of 168 Tire Pressure Monitoring Final Rule(Part V) warning telltale, the potential consequences of significantly under-inflated tires, the meaning of the telltale when it was illuminated, and what actions drivers should take when the telltale is illuminated, to be placed in the vehicle's owner's manual.

The preliminary determination would not have required TPMSs to monitor the spare tire, either when the tire was stowed or when it was installed on the vehicle. It also would not have required the TPMS to indicate a system malfunction.

The agency created the one-tire, 30 percent option so that vehicle manufacturers could continue to install current indirect TPMSs for several more years, thus providing additional time and flexibility for innovation and technological development. The agency created the other option by adjusting the definition of ""significantly under-inflated"" for the four-tire option to 25 percent (instead of 20 percent) so that improved indirect TPMSs and hybrid TPMSs could be used to comply with the TPMS standard. After the phase-in, i.e., after October 31, 2006, the second option would have been terminated, and the provisions of the first option would have become mandatory for all new vehicles.

The agency tentatively believed that a four-tire, 25 percent requirement was preferable for the long-term because it would require TPMSs that warn drivers about all combinations of significantly under-inflated tires and provide more timely and effective warnings. The agency tentatively believed that a one-tire, 30 percent requirement would allow TPMSs that do not warn about all combinations of significantly under-inflated tires and do not provide warnings until the extent of under-inflation reaches 30 percent below the placard pressure. Thus, it appeared that a four-tire, 25 percent requirement would better fulfill the purposes of the TPMS mandate in the TREAD Act, while encouraging further improvements in TPMS technology.

30NHTSA assumed that drivers would respond differently to different information displays. To get the upper bound, the agency assumed that manufacturers that installed direct TPMSs would also install a display showing the pressure of each tire. Currently only direct TPMSs are capable of displaying individual tire pressure. The agency also assumed that 33 percent of drivers would respond to such a display by re-inflating their tires when they became under-inflated by 10 percent, and that the other 67 percent would respond by re-inflating their tires when they became under-inflated by 20 percent, i.e., when the warning telltale would have been activated. To get the lower bound, the agency assumed that manufacturers would install only a low tire pressure warning telltale, as would have been required. Thus, all drivers would not re-inflate their tires until they became under-inflated by 20 percent, and the warning telltale was activated.

31 The net cost is the vehicle cost plus the maintenance cost minus the fuel and tread wear savings. The difference in costs is due to the cost of adding an individual tire pressure display. The agency assumed that manufacturers would install direct TPMSs on vehicles that are not file:///C|/DocumentsFOR andUSE Settings/Robin/Desktop/NHTSA BY PURGEN98 DEALERS TPMS ONLY Summary.htm (3 of 4)12/11/2005 11:41:19 AM Page 98 of 168 Tire Pressure Monitoring Final Rule(Part V) equipped with ABS because the cost of adding a direct TPMS was significantly less than the cost of adding ABS and an indirect TPMS.

32 One TPMS manufacturer, IQ-mobil Electronics of Germany, indicated in its comments that it has developed a pressure sensor that does not require a battery.

33 The phase-in schedule was as follows: 10 percent of a manufacturer's affected vehicles would have had to comply with either compliance option in the first year; 35 percent in the second year; and 65 percent in the third year. In the fourth year, 100 percent of a manufacturer's affected vehicles would have had to comply with the long-term requirements, i.e., the four-tire, 25 percent compliance option.

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Tire Care and Maintenance: Protecting the Environment, Your Investment and Your Safety

Introduction

Tire use has a significant impact on our environment, primarily through the generation of used tires and excess use of fuel. Improperly maintained tires wear faster, use more fuel and can become unsafe.

The largest Canadian tire maintenance issue and biggest contributor to the problem of tire wear is tire under inflation. In a recent study, 70 percent of vehicles surveyed had one or more tires improperly inflated by more than 10 percent, and 56 percent had one tire under inflated by more than 10 percent, including 23 percent that had one or more tires under inflated by more than 20 percent. 1

Although it is normal for tires to wear out over time, you can take steps to prolong the life of your tires.

How to measure tire inflation and other important maintenance steps, such as wheel alignment and tire balancing, rotation, repair and storage, will be discussed.

Aggressive driving habits, high-speed driving, rough use, rough roads and other adverse conditions can also cause premature wear, waste fuel and create hazardous driving conditions.

Contents

1. The Environmental Impact of Improperly Maintained Tires 2. The Effects of Tire Inflation on Fuel Consumption, Tread Wear and Safety 3. Other Factors Affecting Tread Wear 4. Proper Tire Care and Maintenance A. Monthly Inspection B. Tire Inflation C. Wheel Alignment D. Tire Balancing E. Tire Rotation F. Tire Repair G. Tire Storage 5. Key Points to Remember

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1. The Environmental Impact of Improperly Maintained Tires

Used Tires

Improper maintenance shortens the life of your tires. Replacing your tires more often means that more tires go to landfills or recycling centres, and more energy is then used to produce new tires or to recycle them. This has an impact on climate change, the environment and our health.

Canadians scrap approximately 28 million tires every year – approximately one tire for every Canadian. It is estimated that 41 percent are converted into “crumb,” 14 percent are used for molded products, 21 percent are used in tire-derived fuel, and the remaining 24% are export sales. 2

The energy and material used to manufacture four tires is equivalent to 26 litres of gasoline, so just a 10 percent improvement in tire life will deliver significant environmental benefits.3 For example, it would mean 2.8 million fewer used tires, along with a reduction in the gasoline and other types of energy required to transport, dispose of or recycle them. The energy equivalent to 2.8 million tires, approximately 18 million litres of gasoline, means preventing 43 600 tonnes of carbon dioxide (CO2) from entering the atmosphere.

Increased Fuel Consumption

Canada’s 17.6 million light duty vehicles4 consumed about 38.3 billion litres of fuel in 2000,5 an average of 2060 litres each. Tire rolling resistance is one of the main factors affecting fuel consumption variations (good and bad) at urban driving speeds; and rolling resistance is most affected by tire inflation. Each 5 percent (typically 14 kPa or 2 psi) of under inflation translates into 1 percent of increased fuel consumption. For every additional litre of fuel consumed, 2.4 kg of CO2, a major greenhouse gas contributing to climate change, is emitted into the atmosphere, not to mention the other exhaust emissions produced. Based on a weighted average of under-inflated tires, the overall annual cost to Canada’s light duty vehicle population is almost 643 million additional litres of fuel consumed, or about $500 million (based on average pump fuel price of $0.79/L) and 1.54 additional megatonnes of CO2 being emitted into the atmosphere.

2. The Effects of Tire Inflation on Fuel Consumption, Tread Wear and Safety

Effects of Under Inflation

Under inflation is a key safety factor. At low pressures, the tire sidewall has increased sidewall flexing that causes excessive heat build up. This weakens the tire and makes it prone to blowouts or other failures.

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Your car will use more gas if your tires are under inflated, due to increased rolling resistance. The commonly accepted ratio in the automotive industry is that fuel consumption increases 1 percent for every 5 percent of under inflation6. (See Table 1.)

Tires that are under inflated have a reduced contact patch, as they ride just on the edges of the tread. This increases tire wear and reduces grip, adversely affecting handling and stopping distances. Prolonged under inflation develops a distinct wear pattern on the tread face. (See Figure 2, “Shoulder wear.”)

Running one tire at 180 kPa (26 psi) instead of a recommended 220 kPa (32 psi) could reduce the life of that tire by 10 000 km and can increase fuel consumption by up to 3 percent.

In fact, tires rely on pressure to maintain the grip between the tire’s bead (the edge of the tire) and the rim of the wheel. If the pressure is too low, the tire could separate from the rim under aggressive handling or accident avoidance.

Under-inflated tires may squeal when stopping or cornering even at moderate speeds, particularly on warm pavement.

Table 1. The Effects of Under Inflation on Tire Wear and Fuel Use7

Percentage of Percentage Wear Fuel Use Increase Under Inflation Increase 10% 5% 2% 20% 16% 4% 30% 33% 6% 40% 57% 8% 50% 78% 10%

Effects of Over Inflation

A tire that is over inflated rides on just the centre portion of the tread. This causes premature wear in a distinctive pattern. (See Figure 2, “Centre wear.”) The smaller contact patch means reduced grip on the road causing handling problems such as poor steering and stopping. Although higher tire pressure could mean lower rolling resistance and therefore lower fuel consumption, there is a limit – higher tire pressure also leads to a harsher ride, potential increased wear of steering and suspension components, and reduced tire life. Tires are designed to give their best operating performance on any specific vehicle at the inflation pressure shown on the vehicle information placard. This recommended pressure should be respected.

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3. Other Factors Affecting Tread Wear

Driving fast will substantially reduce the life of your tires. As shown in Figure 1, tread life declines rapidly with increasing speed, wearing about 35 percent faster at 110 km/h than at 80 km/h.8

Figure 1. The Impact of Speed on Tire Wear

The type of road surface that you drive on most often will also affect the tire’s life. Driving on rough, unpaved country roads can cut your tire’s life in half.

Premature tire wear can also be caused by numerous mechanical conditions in your car. Worn or loose steering or suspension parts, misalignment and improper mounting and balancing can all contribute.

Drivers can prolong the life of their tires by reducing speed, driving less aggressively and performing regular maintenance. Some simple tire maintenance steps could substantially reduce the number of tires scrapped, with energy and environmental benefits accruing to all Canadians. Purchasing high durability tires will also help reduce the number of used tires generated each year.

4. Proper Tire Care and Maintenance

A. Monthly Inspection

Regular tire care and maintenance is the key to the well being of your tires and your safety. Perform the following actions at least once a month: • Measure your tires’ pressure when they are cold, using a good quality tire gauge (you can’t tell whether a tire is under inflated just by looking at it). • Inspect the tread for signs of uneven wear. • Inspect the tire for embedded stones, glass and other foreign objects that could work their way into the tire and cause a leak.

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• Check the remaining tread depth – tires are manufactured with a “wear bar” that tells you when there is less than 1.6 mm (2/32 inch) of tread depth remaining – when you see this wear bar, the tire must be replaced.

Monitoring tire wear patterns (see Figure 2) can provide you with early indications of suspension and steering component problems, as well as show chronic tire inflation problems. Excessive wear on the inside or outside edges of the tire can indicate alignment problems. Excessive wear down the middle of the tire indicates chronic over inflation. Excessive wear on both outside shoulders indicates chronic under inflation. Feathering, a shredding of the rubber on the outside shoulder, can indicate an alignment problem; and cupping, a repeating bald spot around the tire’s circumference, can indicate a wheel out of balance or a worn suspension. Embedded objects such as stones and glass can cause leaks.

Figure 2. Tread Wear Patterns

Most of the maintenance procedures that can be performed on tires tend to deliver more than one benefit. (See Table 2.) Here’s how to save money, drive more comfortably and safely, and reduce environmental impacts.

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Table 2. Benefits of Proper Tire Maintenance Practices

Prolonged Fuel Better Safety Driving Tire Life Savings Handling Comfort Inflation √ √ √ √ √ Check “cold” once per month Alignment √ √ √ √ √ Check annually, or every 25 000 km Balancing √ √ √ √ √ Every 20 000 km, or when vibrations develop Rotation √ √ Every 10 000 km

Note: Service interval recommendations are the average. See your owner’s manual for specific details.

B. Tire Inflation

Measure your tires’ inflation pressure at least once a month, or when the temperature changes abruptly.

Changes in ambient temperature cause changes in tire pressure, which is particularly important in Canada’s climate where temperature swings of 15 to 20°C are not uncommon. Every 5°C change in temperature results in about a 7-kPa (1- psi) change in tire pressure, so a temperature drop of 15°C would result in approximately 10 percent (21 kPa or 3 psi) under inflation.9 Additionally, tires are permeable and losses of up to 14 kPa (2 psi) per month are not uncommon – more in hot weather, as the pores in the tire material expand.10

Tire valves may become worn, and tire damage may result from rough roads, stones and glass. All can result in pressure loss.

Canada’s cold winters present unique challenges for tire installers. For example, on a –10°C day, the ambient air temperature in the service department may be 15°C, a difference of 25°C. Therefore after the car leaves the shop, air pressure in the tires will reduce because of the drop in temperature. Professional installers compensate for the difference by adding the appropriate amount of additional air pressure. This is often referred to as “winter air.”

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Figure 3: Tire Under Inflation Is Difficult to See

It is not possible to tell whether a tire is under inflated simply by looking at it (see Figure 3), except in extreme cases. Drivers should buy and use a good quality tire pressure gauge. Air machine gauges at service outlets are often inaccurate due to the rough use they receive.

Know the Correct Pressure for Your Vehicle

Caution: The “maximum tire pressure” marked on the tire sidewall refers to the pressure required to carry the maximum load of the tire, and is generally not the same as the “recommended tire pressure” for your specific vehicle. To find the recommended tire pressure for your vehicle’s tires, refer to the tire information placard (see Figure 4), which is normally located on the edge of the driver’s door, the doorpost or another conspicuous location. If you cannot find the vehicle placard, check the owner’s manual.

Figure 4: A Typical Tire Information Placard

The placard on your vehicle could differ from this illustration. However, you should be able to retrieve the same information.

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Measure Tire Pressure When the Tires Are “Cold”

All tire and vehicle manufacturer recommendations are based on cold pressures. “Cold” means that the tire has been stationary for at least three hours or has not been driven more than 2 km. A tire will warm up by as much as 35°C in normal operation, depending on the road surface and the type of driving. Most tires reach an equilibrium temperature after about an hour of driving.11

Measure each tire’s pressure (including the spare tire) when cold at least once a month (or any time there is a sudden change in temperature.) If your vehicle has a temporary spare, note that the specified air pressure, as indicated in the owner’s manual or on the vehicle information placard, is higher than for the tires on the vehicle.

C. Wheel Alignment

Wheel alignment should be checked every 25 000 km.

Wheel alignment refers to how the wheels are set relative to the main driving axes of the vehicle. Alignment consists of toe, camber and caster (see Figure 5); and if any of these is out of adjustment, the tires will drag instead of rolling freely. This will increase fuel consumption, reduce tire life and cause handling and ride problems.

Figure 5: Toe, Camber and Caster

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Symptoms of poor alignment are that the steering pulls to one side or that there is excessive wear on the inside or outside edges of the tire. If you are driving at low speed on straight and level ground, such as in an empty parking lot, and slowly release the steering wheel, your vehicle should continue to travel straight ahead. If it pulls to one side, it could need its alignment adjusted. Pull can also be caused by an under-inflated tire or a dragging brake, both of which waste fuel.

Wheels could be knocked out of alignment at any time by hitting potholes, curbs or other obstacles. Alignment should be checked once a year, or every 25 000 km. Check your owner’s manual.

Steering and Suspension Components

The tires act as an extension of the car’s steering and suspension.

The shock absorbers are there to dampen vibration (it’s the springs that absorb most of the shock from a rough road, with the tire helping out) and to keep all four tires in contact with the road surface. Struts are suspension components that include the shock absorber and the spring in one unit. There are also various steering linkage components that wear over time. Any excess wear in these components could mean that alignment settings cannot be maintained, affecting handling and resulting in premature tire wear and increased fuel consumption.

D. Tire Balancing

Tires should be balanced approximately every 20 000 km, or when drivers feel a vibration.

A typical tire and wheel assembly weighs about 20 kg (44 lbs.). A difference of as little as 14 grams (½ oz.) in the distribution of the overall mass of the assembly is enough to cause a vibration or “shimmy.” A vibration felt in the steering wheel suggests that the front wheel is out of balance (has an imbalance), whereas vibration felt in the driver’s seat usually means the rear wheel is out of balance (has an imbalance).

To balance your wheels, trained professionals use a Dynamic wheel balancer. Small lead weights are added to the rim to bring the wheel into balance, eliminating both up-and-down (tramping) movement caused by static imbalance, and side-to-side (shimmying) movement caused by dynamic imbalance.

Figure 6: Wheel Imbalance

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The fuel economy cost of having one or more tires out of balance is hard to estimate, as it depends on the degree of imbalance and the type of driving. However, because the vehicle now has to overcome a vibration component as well as rolling resistance, there is clearly a fuel economy penalty.

There is also a vehicle maintenance issue. At highway speeds, a typical passenger tire rotates at 14 times per second. Out-of-balance tramping and shimmying will shorten the life of other suspension components and will produce uneven tire wear. Out-of-balance tires can exhibit “cupping,” a wear pattern that looks like a series of bald spots around the tire’s circumference.

E. Tire Rotation

Rotate tires according to the vehicle owner’s manual for maximum tread life.

The front tires work harder as they must bear the scrubbing action of steering as well as rolling wear. This wear is increased in the case of a front-wheel-drive vehicle. Rotating the tires, so that the front tires become back tires for part of their life, will prolong the service life of all tires. If a full-size spare is available, it should be a part of the rotation pattern, which is described in the vehicle owner’s manual. Common practice is to rotate tires every 8 000 to 10 000 km. Always consult your owner’s manual before rotating the tires.

Figure 7: Suggested Rotation Patterns

Front- and Four-Wheel Drive Rear-Wheel Drive

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Note: Vehicles with different size tires on front and back and vehicles with a full- sized spare require different patterns. Consult the owner’s manual for details.

F. Tire Repair

Any tire that has received a puncture in the tread area, or has been driven for even a short distance at very low pressures must be demounted and inspected for damage by a tire professional. Punctures and nail holes up to 0.6 mm (¼ inch) in diameter in the tread area may be patched permanently from inside the tire. A combination patch/plug, which seals the innerliner of the tire and seals the actual puncture so that salt and moisture cannot get into the tire plies, is necessary. Consult a tire professional for the manufacturer’s recommendation before attempting sidewall repairs.

Caution: Speed Rated tires can be repaired, but such repair may reduce or void the speed rating. Consult a tire professional for advice.

G. Tire Storage

Tires should be stored upright in clean conditions, free from exposure to sunlight or strong artificial light, heat, ozone (electrical motors) and hydrocarbons. If stored on rims, the tire pressure should be reduced to approximately 96 kPa (15 psi) to avoid possible cracking and deformation.12

5. Key Points to Remember

1. Properly maintained tires are safer, more comfortable, last longer and use less fuel. 2. Reducing fuel consumption and increasing tire life has a significant and positive impact on the environment and saves money for drivers. 3. Under inflation is the leading cause of tire failure and a major contributor to excessive fuel use and rapid tire wear. 4. 12Air pressure should be measured, and tires inspected, at least once per month. 5. Tire pressure should always be measured when tires are “cold.”

FOR USE BY PURGEN98 DEALERS ONLY Page 110 of 168 • The Autosmart Fact Sheet Series

References

1 Rubber Association of Canada 2003 Tire Survey

2 Rubber Association of Canada

3 Rubber Association of Canada

4StatsCan, Canadian Vehicle Survey, Quarter 4, 2002

5StasCan, Energy Statistics Handbook, Quarter II, 2002

6 Studies by the Shell, Environmental Protection Agency (USA), and tire companies such as Michelin and Bridgestone as referenced in technical support information.

7Prepared by Natural Resources Canada, Office of Energy Efficiency, using data referenced in 5 & 6.

8 Pirelli & C.S.p.A.

9 Transport Canada

10Tire Industry Council

11Tire Industry Safety Council, Motorist @ Tire Care and Safety Guide, 1995

12 European Tyre and Rim Technical Organisation 2002

FOR USE BY PURGEN98 DEALERS ONLY Page 111 of 168 TMC (Technology & Maintenance Council)

TMC Tire Air Pressure Study - May 2002

Conducted by TMC's Tire Debris Prevention Task Force Under the S.2 Tire & Wheel Study Group

This task force was created with the purpose of reducing the incidence of tire debris littering the nation's highways and preventing regulations that restrict retreading. To accomplish these objectives, the Task Force conducted surveys and analysis of tire road debris to ascertain its cause.

• 90% of the tire failures examined were caused by underinflation, which had either existed for a substantial period of time or had been caused by road hazards.

TMC also secured a booth at 2 large events: The Walcott Truckers Jamboree and the Reno Truckerfest 2001 and sent field service engineers to take and record tire pressure. Driver permission to check tire pressures was obtained in the booth or in the truck parking lots by their signing a two-part NCR tire form specifically designed by TMC for recording tire pressure. Vehicles were required to be parked at least three hours before pressures were checked, allowing for cold, accurate tire pressure. This study included 35,128 tires. These tires were on a total of 4,786 trucks and tractors, 1,301 trailers and 1500 motor coaches. This report has a summary of these stunning findings of underinflation.

Upon request the complete studies can be obtained by contacting:

Technology & Maintenance Council 2200 Mill Road, Alexandria, VA 22314 703/838-1763 E-mail: [email protected] Web site: http://www.trucking.org

FOR USE BY PURGEN98 DEALERS ONLY Page 112 of 168 TOYO TIRE TALK

Subject : INFLATION PRESSURE -part2 --- Proper Inflation pressure

In the first of the series, we strongly recommended diligent inflation maintenance for preventing 'underinflation' and increasing safety. The aim for inflation maintenance is preventing tire damage caused by 'underinflation'.

Proper inflation also improves various tire performance, such as even wear, increased traction, handling, lower rolling resistance, and ride comfort.

It's not always easy to find the recommend inflation pressures. Some of your customers may be incorrectly inflating their tires.

Therefore, we strongly recommend you to advise them on correct pressures.

Tire Information Placard on a Vehicle

Above photographs are examples of the 'Tire Information placard' on a vehicle. There is various information regarding the OE tires printed on the placard. Most importantly the vehicle manufacture's recommended inflation pressures can be found on this. The 'Tire Information Placard' can be located in various places; such as the door jam or glove box.

This is the best place to get information regarding 'Proper inflation'.

FOR USE BY PURGEN98 DEALERS ONLY Page 113 of 168 TOYO TIRE TALK

Tire Load-Pressure Table (provided on standard; TRA ETRTO etc.)

The table above is provided in the 2001 TRA Year Book. It shows the designed maximum load capacity calculated at each inflation pressure, but not the recommended pressure.

Maximum Inflation Information on Tire Sidewall

As shown above, tires have the maximum load and pressure indicated on the sidewall. Many drivers misunderstand this as the correct inflation pressure for the tire. It is the maximum cold inflation pressure, not the 'proper inflation' pressure.

As we have seen, there is a lot of information regarding tire pressures, but some don't express 'proper inflation' for a vehicle. In many cases this will only confuse your customers.

Therefore informing your customers about 'proper inflation' is one of the most important jobs for us.

In this TTT, we explained where to find the 'Proper Inflation' pressure for the original equipment tire on the vehicle. We will introduce 'Proper Inflation' for plus-sizing in the near future.

FOR USE BY PURGEN98 DEALERS ONLY Page 114 of 168 TOYO TIRE TALK

Subject : INFLATION PRESSURE Tire Trouble due to Underinflation

1. INTRODUCTION JATMA ( THE JAPAN AUTOMOBILE TIRE MANUFACTURES ASSOCIATION , INC. ) had carried out on the road tire examinations (highway and local road) 151 times between January and December , 2000.

The result of tire examinations is as follows. 2000 1999 Highway local road Total Highway locaTl orotadl Number of checking a vehicle 5,786 8,123 13,909 2,612 10,179 12,791 vehicles with poor tire maintenance * 1,204 1,211 2,415 409 1,328 1,737 Defective percent 20.8% 14.9% 17.4% 15.7% 13.0% 13.6%

The items of poor tire maintenance Highway Loca road Total Number of %Number of %Number of % tires tires tires Underinflation 648 48.1 226 16.4 874 32.1 Insufficient Depth 317 23.5 507 36.8 824 30.3 Irregular wear 199 14.8 416 30.2 615 22.6 Damaged tire 59 4.4 54 3.9 113 4.1 Nail through 42 3.1 31 2.3 73 2.7 Other 82 6.1 142 10.3 224 8.2 Total ** 1347 100.0 1376 100.0 2723 100.0 The discrepancy between * and ** is because of that there is two or more tires with poor maintenance on one vehicle.

As the above table shows , the main item for poor tire maintenance is Underinflation. Especially in highway examinations, "Underinflation" has about 50% share of the above items. " Underinflation " may cause tire failure and is a dangerous condition. That's why, JATMA is advertising the importance of air pressure management.

As you know, the demand of the low aspect ratio tires is increasing all over the world. The flexible point ( shoulder - side area ) of those tires is narrower than compared with standard tires. Thus, it is very difficult to determine whether tires are properly inflated just by looking at them. The checks show that there are many tires which do not have the correct air pressure.

So we would like you to have a new understanding that the most important factor is inflation pressure and that various problems are caused by insufficient or careless pressure maintenance.

Now, we would like to show the dangerous problems caused by underinflation.

FOR USE BY PURGEN98 DEALERS ONLY Page 115 of 168 TOYO TIRE TALK

2. PHOTO SUMMARY TREAD SEPARATION (BELTS SEPARATION)

CAUSE: 1 UNDERINFLATION OR OVERLOAD 2 SEPARATION DUE TO INJURY

BUTTRESS CRACK/SPLIT

CAUSE: 1 UNDERINFLATION OR OVERLOAD 2 EXCESSIVE TORQUE APPLIED TO SHOULDER DURING CORNERING 3 RUBBER COMPOUND

DIAGONAL/TORQUE CRACKING

CAUSE: 1 UNDERINFLATION 2 RUBBER COMPOUND

CHAFER SEPARATION

CAUSE: 1 UNDERINFLATION OR OVERLOAD 2 SEPARATION DUE TO INJURY

FOR USE BY PURGEN98 DEALERS ONLY Page 116 of 168 TOYO TIRE TALK

STEEL PLY RUPTURE-UNDERINFLATION (ZIPPER)

CAUSE: 1 TIRE RUN UNDERINFLATED 2 CONTINUED TO RUN AFTER AIR LOSS 3 OVERLOADING 4 MOISTURE PENETRATING STEEL CORD CAUSING RUSTING

When you push the side area of tire, you can hear " click sounds ". The tire is dangerous to inflate !

RUN FLAT

CAUSE: DEFORMATION OF THE CASING CAUSED BY RUNNING TIRE AT EXTREME LOW INFLATION FOR A LONG DISTANCE

3. CONCLUSION

It is very dangerous for a tire to operate at less than the proper air pressure. This makes it very important to maintain the recommended air pressure and we recommend that the tire pressure be checked at least every week. It is also very important to check air pressure BEFORE the start of a long journey Of course , the inflation pressure must be checked while tires are still cold.

We will issue the TTT which covers " INFLATION PRESSURE PART-2 ( proper air pressure ) " in the near future .

FOR USE BY PURGEN98 DEALERS ONLY Page 117 of 168

Research Note U.S. Department of Transportation DOT HS 809 366 National Highway Traffic Safety Administration November 2001

Air Pumps at U.S. Gas Stations: Major Findings Regarding Availability, Reliability and Fees

Joseph Stevano, M.S., Ph.D.

Tire manufacturers, auto manufacturers Background and experts in consumer safety all emphasize the importance of In response to the rulemaking maintaining proper tire pressure for its requirement of the Transportation Recall positive effect on driver safety, fuel Enhancement, Accountability, and economy and tire longevity. Since the Documentation (TREAD ) Act, the typical motorist owns neither an air National Highway Traffic Safety pump nor a pressure measuring gauge, Administration (NHTSA)’s National gas station air pumps and gauges play Center for Statistics and Analysis an important role with respect to driver (NCSA) conducted the National safety and the conservation of scarce Automotive Sampling System (NASS) resources. Tire Pressure Special Study (TPSS) in February 2001. Although the main Accordingly, this study quantifies and purpose of the TPSS was to quantify the analyzes the major components prevalence and magnitude of tire under- associated with the gas station provision inflation, information regarding air pump of air pressure services. These availability, functionality and whether a components can be divided into two fee was charged for pump use was also groups: those associated with the collected from the gas stations in the provision of air --whether an air pump is sample. This information was present, whether it works and whether a supplemented by the NASS Air Pump fee is charged for its use-- and those Gauge Accuracy Special Study associated with the measurement of air (APGAS) which went back (August pressure --whether a gauge is present 2001) to those gas stations identified in and, if so, how accurately it performs its the TPSS study as having working air task. Hence, this study has been pumps equipped with pressure gauges. divided into five parts: pump availability; The twin purposes of the APGAS were: pump functionality; gauge availability; 1) to evaluate the accuracy –at specified gauge accuracy; and pump fees. pressure levels (25, 35, 45, 55 psi)-- of the station’s pressure gauge; and, 2) to identify the type of gauge used. Thus,

Joseph Stevano is a Statistician employed by Rainbow Technologies, Inc., a contractor working for the Mathematical Anlaysis Division of the National Center for Statistics and Analysis.

National Center for Statistics and Analysis 400 Seventh St. S.W., Washington, DC 20590

FOR USE BY PURGEN98 DEALERS ONLY Page 118 of 168 in this report the data regarding the of gauge was used: a Longacre Model measurement of gauge accuracy come 50402 0-60 psi Tire Pressure Gauge). from the APGAS, while all of the other The uniform procedure consisted of: data come from the TPSS. i. taking the measurements in the Survey Methodology above order;

In the TPSS, the gas stations were ii. for each level, first bleeding the sampled using a multi-stage selection tank to at least 20 psi less than the process1 whose goal was to obtain a reference level3; sample of gas stations -from all regions of the country- that were as iii. refilling the tank to the reference representative2 as possible. level (as measured by the station’s gauge); and, then, The APGAS was designed to ensure that the measurement and gauge iv. measuring the actual pressure identification data were as accurate as using the researcher’s gauge. possible by controlling for: iv. The day’s second set of i. the equipment used; measurements was then obtained by repeating this same process in the ii. time of day at which same order. measurements were taken; In addition to ensuring uniformity of iii. pressure levels at which the procedure and equipment, a special reference pressures were set; and effort was made to make recorded measurements as independent as iv. the procedure followed to take the possible by: pressure measurements. i. taking 4 different readings at At each gas station, an identical device each reference pressure level; (Air Works 7 gallon Portable Air Tank) was pressurized using the station’s ii. having the readings taken on two pump to reference pressure levels different days (two each day) by (measured using the station’s gauge ) of 25, 35, 45 and 55 psi. For each of these iii. two different researchers who levels, a corresponding measurement were instructed to was recorded using the researcher’s gauge (in every case, the same model iv. fax his/her readings to a NASS Zone Center immediately after taking them and to

1 For details, see Research Note, Tire Pressure v. not show or discuss his/her Special Study: Methodology, NHTSA, August 2001, DOT-HS-809-315. measurements with the other 2 However, please note that, since the population researcher. from which these gas stations were drawn consisted of those having at least two islands, all of the estimates reported here refer to gas stations of at least 3 For example, to obtain the 45 psi measurement, the this size. tank would first be bled down to below 25 psi.

National Center for Statistics and Analysis 400 Seventh St. S.W., Washington, DC 20590

FOR USE BY PURGEN98 DEALERS ONLY Page 119 of 168 Finally, the type of gauge the station (accounting for only 14 percent of the had was identified by taking a digital gas stations in the US), the number of photograph of the gauge, which was stations equipped with pumps is then emailed to NHTSA where it’s type estimated to be over 85 percent. could be unambiguously determined.

Results: Pump Availablility

The TPSS results show that it is quite common for gas stations to have air pumps: from these data NCSA estimates that 94 percent of the stations in the US have air pumps. Although this figure indicates that, in general, when a passenger vehicle pulls into a gas station the driver can feel fairly confident of encountering an air pump, it could be masking a possible problem in the sense that stations which have small amounts of traffic - specifically those in sparsely populated areas- may have a much lower probability of being equipped with an air Results: Pump Functionality pump.4 Thus, it would be desirable to get some idea of to what extent pump Pulling into a gas station and finding an availability varies with station traffic. As air pump there is one thing, but what if Chart 1 shows, there appears to be it’s not working? Are non-working strong positive relationship between pumps a problem, or can the consumer pump availability and station traffic. feel reasonably sure that if the station However, even at the lowest traffic level5 has a pump that it will be functioning? The data show that an estimated 9 percent of gas station air pumps will not 4 Since urban areas tend to be well-endowed with gas be working. Thus, when the consumer stations, even if only 80 percent of the stations have pulls into a gas station the probability air pumps, the consumer should have little difficulty that a pump will be there and also that it in finding an air pump equipped station. On the other will be functioning is about 86 percent. hand, a similar percentage in rural areas could point to exactly the opposite conclusion: since there are many fewer gas stations available, if only 80 percent Table 1 of them have pumps, this may mean that some Criteria Used to Partition Stations consumers will have a difficult problem finding air into Traffic Categories pumps. Traffic Number of Vehicles % of Stations in Level in 75 mins Traffic Level 5 The TPSS survey provided the estimates for station 1 0 –15 14% traffic by counting the number of vehicles coming in 2 16 - 25 18% to the gas pumps during five 15 minute periods 3 26 - 35 23% starting at 8 am, 10 am, 12 pm, 2 pm and 4 pm. Thus, 4 36 -45 20% the station traffic was arrived at by taking the sum of 5 46 -60 11% the traffic during these five 15 minute periods. For 6 61 - 75 10% this report, the data was used to partition the stations 7 76 + 4% into 7 traffic levels as shown in Table 1.

National Center for Statistics and Analysis 400 Seventh St. S.W., Washington, DC 20590

FOR USE BY PURGEN98 DEALERS ONLY Page 120 of 168

The next step is to condsider what factors play a role in determining whether a pump is working or not. Since many stations charge a fee for use of the air pump, it is reasonable to investigate the relationship between whether a fee is charged and the probability that that pump will actually be working. A priori, one would think that there should be a positive relationship between the presence of a pump fee and the probability - conditional on a pump being available- that it will actually be working: the reason being that if a fee is charged, then the owner of the pump has more of an incentive to keep it working. Although such a hypothesis seems reasonable, the actual results show the opposite: the presence of a fee actually lowers the probability that the pump will be working: from 95 percent if no fee is charged, to 86 percent in the presence Results: Gauge Accuracy of a fee. One of the most critical items this study set out to discover was exactly how Results: Gauge Availablility much faith the consumer could place on the pressure readings given by the Maintaining proper tire pressure station’s gauge. requires not just using a pump, but also measuring tire pressure. Thus, it is Since the rulemaking goal specified by significant that less than half (49 the TREAD Act concerned coming up percent) of the pump-equipped gas with a system to report under-inflation, stations also have a tire gauge. clearly Congress felt that under-inflation was a more dangerous problem than The next thing to consider is whether over-inflation. The APGAS found that, this has something to do with the fact in general, gas station gauges tend to that most stations (57 percent) do not over-report, rather than under-report, charge a fee for pump use. And, the true tire pressure (thus encouraging indeed, there is a strong relationship the more dangerous under- rather than between gauge availability and pump the less dangerous over-inflation). fees. As Chart 2 illustrates, in the Table 2 and Chart 3, which show the presence of pump fees, estimated distribution of the deviations between gauge availability (conditional on a the station gauge and the reference pump being available) more than gauge for the four reference levels, doubles, going from only 31 percent to illustrate this tendency to over-report. 68 percent.

National Center for Statistics and Analysis 400 Seventh St. S.W., Washington, DC 20590

FOR USE BY PURGEN98 DEALERS ONLY Page 121 of 168

Table 2 Amount of Deviation (psi) of Station Gauge from Reference Gauge By Percentiles* Station Percentiles Gauge Pressure 5th 10th 20th 25th 40th 50th 60th 75th 80th 90th 95th (psi) 25 -7.3 -4.5 -1.3 -0.7 0 0.3 0.7 2 3.1 4.6 5.3 35 -5 -3.5 -0.4 0 0.5 0.8 1.4 2.5 3 5.4 6 45 -5.9 -3.3 0 0 0.8 1 1.7 3 3.1 6.3 8 55 -2.7 -1 -0.2 0 1 1.5 2.3 3.4 3.9 6.8 8.1 * Note: Negative values indicate under-reporting: measurement of the station gauge is less than the researcher’s gauge. Positive values indicate over-reporting: measurement of the station gauge is greater than the researcher’s gauge. Source: National Center for Statistics and Analysis, NHTSA, APGAS Survey, Aug. 2001

45 psi, about 32 percent of station gauges over-report by this amount; while at 55 psi, about 45 percent of station gauges over-report pressure by at least 2 psi.

While over-reporting of 2 psi may not be significant, many station gauges did over report by a substantial amount. Table 3 shows the percentage of station gauges over-reporting by 4 psi or more.

Table 3 Over-Reporting by Station Gauges By Pressure Levels and Level of Over-reporting (Percent Over-reporting) Station Percent over-reporting Gauge by 4 by 6 by 8 Pressure psi or psi or psi or (psi) more more more The APGAS also found that the higher 25 16 2 0 the recommended tire pressure, the 35 19 9 0 greater the probability of encountering a 45 19 14 5 station whose gauge will over-report the 55 20 15 9 actual pressure (leading motorists to Source: National Center for Statistics and Analysis, NHTSA, APGAS Survey, Aug. 2001 under-inflate their tires). For example, at a pressure level of 25 psi, 25 percent of As Table 3 shows, at a pressure level of station gauges over-report pressure by at 45 psi, 5 percent of station gauges over- least 2 psi; at pressure levels of 35 and

National Center for Statistics and Analysis 400 Seventh St. S.W., Washington, DC 20590

FOR USE BY PURGEN98 DEALERS ONLY Page 122 of 168 report tire pressure by 8 psi or more; percent of the hand held gauges over- while at a pressure level of 55 psi, over- reported by at least 4 psi. reporting of this magnitude occurs at nearly one station in ten. Finally, the 17 gauges were partitioned7 into digital and non-digital (i.e., dial and Between (depending on the pressure pencil) gauges. The mean deviations for level) 16 and 20 per cent of gas station non-digital gauges ranged from 1.3 psi gauges over-report pressures by at least (pressure levels, 35-45 psi) to 1.8 psi 4 psi (Table 3). Thus, for about one gas (pressure level, 55 psi); in contrast, digital station in five, it will be the case that a gauges showed a mean deviation of 0.1 motorist filling his tires to the to 0 psi at all pressure levels. recommended pressure will, in fact, have unknowingly under-inflated them by at least 4 psi.

At 35 psi, which is at or close to the recommended tire pressure for most passenger cars and SUVs, 9 percent of station gauges over-report by 6 psi or more. That is, at nearly one station in ten, the motorist relying on the station gauge to fill the tires of his car or SUV to their recommended pressure will, in fact, be unknowingly under-inflating them by 6 psi or more.

Given these findings, the question arises as to whether a motorist would be better off bringing his own gauge. NHTSA’s Vehicle Research and Test Center (VRTC) tested 17 new6 commercial gauges and found that, as was the case with gas station gauges, hand held gauges tend to over- rather than under- report pressures (thus encouraging under-, rather than over-, inflation). Mean Results: Pump Fees deviation from the reference gauge ranged from 0.6 psi (at a pressure level of Overall, an estimated 43 percent of the 55 psi) to 1.6 psi (at a pressure level of pump-equipped gas stations in the US 25 psi). Five percent (Chart 4) of the charge a fee for use of their air pump. hand held gauges over-reported However, this study found that whether or pressures by at least 4 psi (pressure not a fee is charged varies greatly (Chart level, 25 psi) while, at the other pressure 5) from region to region. levels, between 2.5 percent and 0

7 The measurement mechanism of dial/pencil gauges is 6 Thus, unlike the gas station data, the hand gauge data fundamentally different from that of digital gauges: does not reflect the impact of wear and tear on gauge the latter is mechanical while the former is electronic accuracy. (Chip Chidester/Art Carter, NHTSA).

National Center for Statistics and Analysis 400 Seventh St. S.W., Washington, DC 20590

FOR USE BY PURGEN98 DEALERS ONLY Page 123 of 168 the estimated probability that that air pump will also have a gauge8 is only around 50 percent.

6) The presence of a pump fee substantially increases the probability that a station will have an air pump equipped with a tire pressure gauge.

7) Station gauges tend to over-, rather than under-, report the true tire pressure (thus encouraging the more dangerous under- rather than the less dangerous over-inflation).

8) The magnitude by which station gauges over-report tire pressure is significant: between 16 percent and 20 In the West only 18 percent of the gas percent of station gauges over-report by stations charge a fee for pump use, while at least 4 psi (all pressure levels); for in the South, fees are charged 63 percent pressures of 35-55 psi, between 9 of the time. percent and 15 percent over-report by at least 6 psi while for pressure levels of 45- Conclusions 55 psi, between 5 percent and 9 percent of station gauges will over-report by 8 psi 1) Overall, the probability that a randomly or more. selected gas station will have an air pump is 94 percent. 9) Like station gauges, hand held gauges tend to over- rather than under-report tire 2) Pump availability does vary positively pressures (thus leading motorists to with the volume of traffic through a gas under-, rather than over-, inflate their station: the higher the traffic, the more tires). Nevertheless, hand held gauges likely it is to have an air pump (there were not only much less likely to over- appears to be a high floor for this report tire pressures by 4 psi or more but, percentage: even among those stations unlike station gauges, none of the hand in the lowest quintile of volume, the helds over-reported by more than 8 psi. probability that they would have a pump available is still in excess of 85 percent). 10) Overall, about 43 percent of U.S. gas stations charge a fee for pump use. 3) Overall, the probability that a randomly selected gas station will have a 11) The probability that a fee will be functioning air pump is 86 percent. charged for pump use is regionally dependent (varying from a low of 18 4) Surprisingly, if a fee is charged for use percent in the West to a high of 63 of a pump, the probability is greater that percent in the South). the pump will not be working.

8 5) Given that a station has an air pump, I.e., the probability that a gas station will have a tire gauge conditional on it having an air pump.

National Center for Statistics and Analysis 400 Seventh St. S.W., Washington, DC 20590

FOR USE BY PURGEN98 DEALERS ONLY Page 124 of 168 Concluding Note pressure by at least 4 psi. At 35 psi, nearly one station in ten will give a With respect to tire gauges, two things reading which exceeds the actual must be emphasized. First, only about 50 pressure by at least 6 psi (thus, a motorist percent of station pumps are equipped inflating his tires to a recommended with a gauge. Secondly, gas station pressure of 35 psi will, in fact, pull out of gauges tend to over-report tire pressures such stations with an actual pressure of (i.e., give readings which exceed the 29 psi or less). actual pressure). Consequently, motorists who rely solely on a station Finally, most drivers do not randomly gauge to evaluate their pressure face a select the gas station at which they check high probability of unknowingly under- their tire pressures -instead, they inflating their tires. For both these probably have a particular gas station reasons it is advisable that motorists which they frequent and at which they bring and use their own gauge. check their tire pressure. Thus, without even realizing it, at about one station in How seriously could they be under- five it is the case that drivers who rely on inflating their tires? It depends on the the station’s gauge to check their tire pressure to which they inflate their tires. pressure are using a gauge that over- In the 25-35 psi range (the recommend- reports the pressure by 4 psi or more, ed tire pressure range for virtually all thus causing them to under-inflate their passenger cars and SUVs) nearly one tires by this amount. station gauge in five will over-report tire

For additional copies of this research note, please call (202)366-4198 or fax your request to (202)366-3189. For questions regarding the data reported in this research, contact Joseph Stevano [202-366-2219] of the National Center for Statistics and Analysis. This research note and other general information on highway traffic safety may be accessed by internet users at http://www.nhtsa.dot.gov/people/ncsa.

U.S. Department of Transportation National Highway Traffic Safety Administration 400 Seventh Street, S.W., NRD-31 Washington, D.C. 20590

FOR USE BY PURGEN98 DEALERS ONLY Page 125 of 168 Michelin | Press Release: INFLATION, ROTATION AMONG KEY TIPS FOR TIRE SAFETY WEEK

Dealer Contact Locator Us

Home > Press Releases > INFLATION, ROTATION AMONG KEY TIPS FOR TIRE SAFETY WEEK

Michelin Expert Offers Advice for Safe Driving Year 'Round.

GREENVILLE, S.C. (April 25, 2003) – Whether they know it or not, good drivers go through a subconscious, mental checklist before hitting the road. Fill the gas tank. Check. Adjust the mirrors and seat. Check. However, most drivers neglect a quick inspection of their tires and that can prove dangerous and costly.

According to the National Highway Traffic Safety Administration (NHTSA) at the U.S. Department of Transportation, one of every four (27 percent) passenger cars on U.S. roadways has one or more under inflated tires. NHTSA estimates that proper tire inflation could help save about 50 to 80 lives and prevent 6,600 to 10,600 injuries each year. Additionally, the Rubber Manufacturers Association (RMA) estimates that 250,000 crashes a year result from improperly inflated tires.

As the RMA's National Tire Safety Week (April 27 to May 3, 2003) kicks off the summer travel season, the tire experts at Michelin offer advice to anyone planning an adventure in their vehicle.

"It's senseless for even one traffic fatality to happen because of under-inflated tires," says Mac Demere, Michelin test track driver and tire safety expert. "Taking five minutes to look over your tires each month should be as automatic as buckling a seat belt — and it's just about as easy."

Demere offers these basic tips for drivers to add to their pre-trip safety check:

● Check tire pressure monthly and before any trip — Before hitting the road, make sure that you have a tire gauge on hand and know how to use it. Low tire pressure makes a new tire perform like an old, worn-out tire. Look for the car-maker's recommended tire pressure setting on the driver's door jamb, on the glove compartment door, or in the owner's manual and inflate tires accordingly. ● Replace tires properly — If you only replace two tires at a time, mount them on the rear axle. Otherwise, your car could lose rear traction in the rain and spin out. ● Check tire tread depth — In most states, the minimum legal tread depth is 2/32 of an inch. If you place a penny in your tire's shallowest groove and you can see the top of Abraham Lincoln's head, it's time to buy new tires. ● Proper alignment is important — Have your car's suspension re-aligned when you buy new tires, if you notice uneven wear or if it has been a while since your last alignment. A suspension that is not aligned properly can wear out new tires after only a few thousand miles and adversely affect gas mileage.

While these tips may seem like common sense to some, a recent Michelin poll revealed that 20 percent of all drivers do not own a tire gauge and a surprising 25 percent have never changed a tire, revealing a huge need for tire safety education.

"A $2 tire gauge, a quarter for the gas station air pump, and five minutes each month are all you need to make sure your tires are road worthy," says Demere. "These simple steps are well worth the minimal effort and can save you time and money in the long run."

Michelin manufactures and sells tires for every type of vehicle, including airplanes, automobiles, bicycles, earthmovers, farm equipment, heavy-duty trucks and the space shuttle. The company also publishes travel guides, maps and atlases covering Europe, Asia, Africa and North America. Headquartered in Greenville, S.C., Michelin North America employs 24,640 people and operates 22 plants in 18 locations.

For additional tire care tips visit www.michelinman.com.

file:///C|/Documents and Settings/Robin/Desktop/Michelin 250000 accidents press release.htm (1 of 2)12/11/2005 7:06:40 PM FOR USE BY PURGEN98 DEALERS ONLY Page 126 of 168 OTHER IMPORTANT INFO… HOW TO TAKE CARE

FOR USE BY PURGEN98 DEALERS ONLY Always buckle your seat belt. OF YOUR TIRES Practice good driving habits, which will help keep Proper tire care and safety is simple and easy. The your tires in good condition. Rubber Manufacturers Association (RMA) recommends SPEED • Obey posted speed limits. LIMIT getting in the habit of taking five minutes every month • Avoid fast starts, stops, 65 to check your tires, including the spare. and turns. If you think you may have a tire problem or are • Avoid potholes and other unsure of the condition of your tires, consult a tire objects on the road. dealer as soon as possible. • Do not run over curbs or hit your tires against the curb when parking. ABOUT THE RUBBER • Do not overload your vehicle. Check your vehicle’s MANUFACTURERS tire information in the owner’s manual for the ASSOCIATION maximum recommended load for your vehicle. Founded in 1915, the Rubber Manufacturers Tire Pressure Monitoring System (TPMS) Association is the national trade association of the Vehicles equipped with Tire Pressure Monitoring rubber industry.yq The association is headquartered in Systems (TPMS) can help motorists detect loss of Washington,gp D.C. and its membership includes more inflation pressure. Federal regulations require TPMS than 100 companiesp that manufacture tires and other to warn drivers when tires are 25% under inflated. rubber products. For many vehicles this warning may be too late to 1400 K Street, NW prevent damage caused by under inflation. TPMS Washington, DC, 20005 units are NOT a replacement for monthly tire pressure 202/682-4800 checks with a gauge. fax 202/682-4854 www.betiresmart.org Nitrogen Nitrogengg gas can be safely y used in place p of compressedpgy air to inflate tires. Nitrogen may aid in RMA TIRE tire pressure retention as it does not seep through a MANUFACTURER MEMBERS: tire as quickly as compressed air. Other sources of potentialppg air loss such as punctures, damage or a Bridgestone Americas Holding, Inc. faultyyyg valve will not be slowed by nitrogen inflation. Continental Tire North America, Inc. Whether tires are inflated with compressedp air or Cooper Tire and Rubber Company nitrogen,gp tire pressure MUST be checked every month Goodyear Tire and Rubber Company to ensure proper tire inflation. Michelin North America Pirelli Tire North America A consumer education program of the Proper tire care helps the environment. Toyo Tire North America, Inc. Page 127 of 168 Under inflated tires waste fuel. Properly inflated tires Yokohama Tire Corporation help promote better fuel economy. Additionally, regular care helps tires get the most potential wear so they don’t need to be replaced as often. The "Be Tire Smart" program is supported by AAA.

FOR USE BY PURGEN98 DEALERS ONLY It’s important to have the proper inflation pressure in Under inflation or overloading creates Tires must be replaced when the your tires, as under inflation can lead to excessive stress and heat, and can lead to tire tread is worn down to 2/32 of tire failure. The “right amount” of failure. This could result in vehicle damage an inch. Traction, particularly in inflation for your tires is specified by and/or serious injury or death. bad weather, and resistance to the vehicle manufacturer and is shown hydroplaning is reduced as tires wear. An easy test: on either the vehicle door edge, door An over inflated tire can cause uneven wear in place a penny into a tread groove. If part of post, glove box door or fuel door. It is the center of the tread. Over inflation also can Lincoln’s head is covered by the tread, you’re also listed in the owner’s manual. make the tire more susceptible to road hazard driving with the proper amount of tread. If damage and pose vehicle handling issues. you can see all of his head, you should Look for this information in your vehicle: buy a new tire. Built-in treadwear indicators, or “wear bars,” which look like narrow strips of ALIGNMENT smooth rubber across the tread will appear on the Misalignment of wheels in the front or rear can cause tire when the tread is worn down to 2/32 of an uneven and rapid treadwear and should be corrected inch. When you see these “wear bars,” the tire is by a tire dealer. Front-wheel-drive vehicles, and those worn out and should be replaced. with independent rear suspension, require alignment Visually check your tires for signs of uneven wear. of all four wheels. Have your alignment checked You may have irregular tread wear if there are high periodically as specified by the vehicle owner's manual and low areas or unusually smooth areas. Consult or whenever you have an indication of trouble such as your tire dealer as soon as possible. “pulling.” • When you check the inflation pressure, make sure Also have your tire balance checked periodically. the tires are cool — meaning they are not hot from An unbalanced tire and wheel assembly may result in driving even a mile. (NOTE: If you have to drive a irregular wear or vibration. TIRE CARE FACTS distance to get air, check and record the tire pressure first and add the appropriate inflation ✔ 27% of passenger cars and 32% of pickup pressure when you get to the pump. ROTATION trucks, SUV’s and minivans have at least It is normal for tires to heat up and one significant under inflated tire.* the inflation pressure inside to Sometimes irregular tire wear can be corrected by rotating your tires. Consult your vehicle owner’s increase as you drive. Never ✔ 9% of tires on the road are bald.* “bleed” or reduce inflation pressure manual, the tire manufacturer or your tire dealer for the appropriate rotation pattern for your vehicle. when tires are hot.) ✔ A tire can lose as much as 50% of its (NOTE: If your tires show uneven wear, ask your tire inflation pressure and not appear to dealer to check for and correct any misalignment, • Remember to check the spare. (NOTE: Some spare be flat. imbalance or other mechanical problem involved tires require higher inflation pressure.) before rotation.) ✔ Inflation pressure in a tire goes up Page 128 of 168 • Visually inspect the tires to make sure there are Before rotating your tires, always refer to your (in warm weather) or down (in cold no nails or other objects embedded that could poke vehicle owner’s manual for rotation recommendations. weather) 1-2 pounds for every 10 degrees a hole in the tire and cause an air leak. Check the If no rotation period is specified, tires should be of temperature change. sidewalls to make sure there are no gouges, cuts, rotated approximately every 5,000–8,000 miles. * Source: National Highway Traffic Safety Administration bulges or other irregularities. (NOTE: After rotation, make sure inflation pressure is set to the vehicle manufacturer’s specification.)

United States Government Accountability Office Washington, DC 20548

February 9, 2007

The Honorable Byron L. Dorgan United States Senate

Subject: Underinflated Tires in the United States

Dear Senator Dorgan:

More than a quarter of automobiles and about a third of light trucks (including sport utility vehicles, vans, and pickup trucks) on the roadways of the United States have one or more tires underinflated 8 pounds per square inch (psi) or more below the level recommended by the vehicle manufacturer, according to a report by the Department of Transportation’s (DOT) National Highway Traffic Safety Administration (NHTSA).1 A decrease in tire pressure can be caused by poor maintenance, driving habits, punctures, road conditions, and the quality of material used in tire construction. According to tire experts, under normal driving conditions, air-filled tires can lose from 1 to 2 psi per month as air permeates through the tires. Vehicles with underinflated tires have had handling problems that caused crashes resulting in fatalities and injuries. In addition, the fuel economy of vehicles driving on underinflated tires is slightly lower. In response to your request for information on these issues, we addressed the following questions: (1) What is the impact of tire underinflation on safety and fuel economy, and what actions has the federal government taken to promote proper tire inflation? and (2) what technologies are currently available to reduce underinflation and what are their implications for safety and fuel economy?

To address these questions, we interviewed officials from federal agencies, tire industry associations and businesses, and public advocacy groups. We examined their studies on tire pressure and its impact on safety and fuel economy, and the technologies used to detect underinflation and maintain tire pressure. Unless otherwise specified, in this report we refer to the nongovernmental organizations that we contacted collectively as “industry.” We also examined federal legislation and DOT requirements on tire pressure monitoring systems (TPMS), DOT’s program for increasing public awareness on maintaining proper tire inflation, and fleet maintenance directives provided by the General Services Administration (GSA) to federal agencies that lease GSA vehicles. Finally, we assessed the methodology that NHTSA used to conduct a survey on tire underinflation and found it, and some of the conclusions derived by the agency from the survey, appropriate for our use in this report. (See encl. I for additional information on our methodology, including a list of

1NHTSA, Research Note: Tire Pressure Special Study (Washington, D.C., August 2001).

GAO-07-246R Underinflated Tires

FOR USE BY PURGEN98 DEALERS ONLY Page 129 of 168 organizations we contacted.) We conducted our work from July 2006 through December 2006 in accordance with generally accepted government auditing standards.

Summary

Underinflated tires impact a driver’s ability to control a vehicle against skidding, blowouts, and other tire failures. While not a leading cause of highway accidents and fatalities, a NHTSA study shows that, in 1999, underinflated tires contributed to 247, or 0.8 percent, of 32,061 fatalities and 23,100, or 0.8 percent, of almost 3 million injuries. In addition, NHTSA estimates that 41 vehicular-related deaths occur annually because of blowouts alone from underinflated tires. Moreover, tires that are not inflated to the appropriate pressure result in a slight decline in fuel economy. The Department of Energy’s designated economist on this issue indicated that, of the 130 billion gallons of fuel that the Transportation Research Board (TRB)2 estimated were used in passenger cars and light trucks in 2005, about 1.2 billion gallons were wasted as a result of driving on underinflated tires. The federal government is using legislation, public information, and educational programs to inform the public about tire underinflation. For example, the Transportation Recall Enhancement Accountability Documentation (TREAD) Act of 2000 required NHTSA to develop regulations for installing a tire pressure monitoring system in new passenger cars and light trucks.3 These regulations are being phased in and will be effective for all new passenger cars and light trucks produced for the 2008 model year. The regulations will require a TPMS that will alert drivers when one or more tires are underinflated 25 percent below the vehicle manufacturer’s recommended inflation pressure or a minimum pressure specified in the regulation, whichever is higher.4 In addition, NHTSA works with industry to promote public awareness of the importance of properly inflated tires, and GSA provides information on the issue to federal agencies, such as DOD, that lease vehicles.

Several technologies are currently available to reduce tire underinflation, and all of them have the potential to increase safety and fuel economy when used appropriately. The federal government and industry recommend using a tire pressure gauge to check pressure regularly and reinflate tires to maintain proper inflation. Also, TPMS equipment for passenger cars and light trucks will alert drivers when a tire’s pressure falls 25 percent below a vehicle manufacturer’s recommended level or minimum activation pressure specified in the regulations, whichever is higher. When there is a need to increase tire pressure, consumers generally have a choice between two products—compressed air and nitrogen. Compressed air is readily available at service stations and retail tire outlets nationwide and is either free or relatively inexpensive for consumers. However, compressed air leaks from tires over time. Nitrogen permeates through tires slower than air and studies have shown that tires

2The Transportation Research Board is a division of the National Research Council of the National Academy of Sciences. See Transportation Research Board, Special Report 286: Tires and Passenger Vehicle Fuel Economy Informing Consumers, Improving Performance (Washington, D.C., 2006), http://onlinepubs.trb.org/onlinepubs/sr/sr286.pdf. 3Public Law 106-414, 114 Stat. 1800 (2000). 4Specifically, the regulations require that the TPMS alert drivers when one or more tires are underinflated 25 percent below the vehicle manufacturer’s recommended cold tire inflation pressure or a minimum activation pressure specified in the regulation, whichever is higher.

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FOR USE BY PURGEN98 DEALERS ONLY Page 130 of 168 filled with nitrogen retain pressure levels longer and age more slowly. However, researchers pointed out that nitrogen has not been assessed under normal driving conditions. Transport Canada, the Canadian government’s transportation ministry, has been studying the benefits of nitrogen inflation in truck tires and expects to complete this work in early 2007. It is unclear when the results of this work will be made public. NHTSA expects to complete testing on nitrogen inflation’s effects on the rate of loss of inflation pressure and nitrogen inflation’s effects on tire aging by April 2007 and March 2007, respectively. Currently, relatively few nitrogen outlets are available for consumers to use, and while the cost of nitrogen varies, it can exceed the cost of compressed air. The materials used to make tire innerliners,5 can affect the amount of air and water vapor permeability. Finally, single-wide tires6 and the use of pressure management and tire pressure monitoring systems on large trucks can also reduce the incidence of underinflated tires.

Underinflated Tires Can Impact Vehicle Safety and Fuel Economy

While underinflated tires are not a significant cause of highway fatalities and injuries, studies indicate that drivers have less control of their vehicles when tires are not properly inflated. In an analysis performed for the TREAD Act, NHTSA estimated that less than 1 percent of passenger vehicle occupant fatalities and injuries occurring in 1999 resulted from loss of control and skidding caused by underinflated tires. Specifically, 247, or 0.8 percent, of 32,061 fatalities and 23,100, or 0.8 percent, of almost 3 million injuries were related to underinflation. NHTSA also estimates that 41 deaths and 1,028 injuries occur annually because of blowouts resulting from tire underinflation. In addition, the International Tire and Rubber Association reported that underinflation was the “single most common” factor in tire failure. Further, NHTSA reported that underinflation influences skidding, hydroplaning, increased stopping distance, flat tires, and blowouts.

Underinflated tires can have a slight impact on fuel economy.7 According to a 2006 congressionally mandated TRB study on fuel efficiency, passenger car and light trucks use an estimated 130 billion gallons of fuel per year.8 In addition, DOE’s designated economist on this issue estimates that vehicles with underinflated tires waste approximately 1.2 billion gallons of fuel per year due to the increased resistance of the tires.

Government Is Taking Steps to Address Tire Underinflation

The federal government has enacted legislation and is using public information and educational programs to inform the public about tire underinflation. Congress enacted the TREAD Act in 2000 in response to reports that tire failures caused by tread separation from certain Firestone tires installed on Ford SUVs and trucks

5Innerliners are the coating laminated to the inside of tubeless tires that provide a barrier between the substance used to inflate the tire (e.g., compressed air) and the tire. 6Single-wide tires are designed to replace dual-mounted tires on trucks—one single-wide tire is mounted on each side of an axle. 7Other factors that affect fuel efficiency include driving habits such speeding, as well as a vehicle’s load. 8 TRB Special Report 286.

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FOR USE BY PURGEN98 DEALERS ONLY Page 131 of 168 that—according to NHTSA—resulted in about 268 fatal crashes from January 1991 to August 2001. In addition to requiring upgrades to the agency’s safety standards for tires, the TREAD Act required NHTSA to develop regulations for a TPMS. In response, NHTSA issued a rule in 2002 that required a TPMS to be installed on new passenger cars and light trucks (i.e., those with a gross vehicle weight rating of 10,000 pounds or less).9 However, some consumer safety groups challenged NHTSA’s rule in court because they were concerned about whether certain types of TPMS allowed under the rule could sufficiently detect tire underinflation. In August 2003, a federal court vacated the rule and directed NHTSA to conduct further rule making that would be consistent with the court’s ruling.10 NHTSA subsequently issued a new rule in 2005 that requires manufacturers to install a TPMS on all new passenger cars and light trucks by the 2008 model year.11 This rule, like its predecessor, is also in litigation.

Two types of TPMS are currently available for some passenger cars and light trucks: direct and indirect. A direct TPMS reads a tire’s inflation pressure level with an electronic device mounted inside the tire either on the valve stem or the wheel, and sends the information via a wireless signal to a receiving unit in the vehicle. In contrast, an indirect TPMS checks the inflation level of a tire by monitoring the rotational speeds of the wheels (using the vehicle’s anti-lock braking system) and identifying rotational differences between the wheels. NHTSA requires both types of TPMS to have an indicator on the dashboard that alerts a driver if the pressure of one or more tires falls either 25 percent below the pressure recommended by the vehicle manufacturer or a minimum pressure specified in the regulation, whichever is higher.12 Once all new passenger vehicles and light trucks are equipped with a TPMS, NHTSA estimates that 119 to 121 passenger car and light truck fatalities will be prevented each year because it expects that 90 percent of drivers with TPMS technology will check and reinflate their tires in response to indications of tire underinflation. In addition, NHTSA estimates that this increased attention will enable drivers to save from $15 to $23 over the life of a vehicle because of better fuel economy. (See encl. II for additional information on TPMS.)

9Federal Motor Vehicle Safety Standard (FMVSS) No. 138 was promulgated through a final rule published in the Federal Register on June 5, 2002 (67 Fed Reg. 38704). 10The groups that participated in the lawsuit were Public Citizen Inc., New York Public Interest Research Group, and the Center for Auto Safety. Public Citizen v. Mineta, 340 F. 3d 39 (2d Cir. 2003). 11FMVSS No. 138, 70 Fed. Reg. 18136 (Apr. 5, 2005); see, also, 70 Fed. Reg. 53079 (Sept. 7, 2005) (Final Rule; responses to petitions for reconsideration). In accordance with our policy, we did not address the matters in litigation. 12The recommended pressure is posted on a label or placard inside the vehicle. NHTSA has developed a table that establishes the lowest pressure levels for various tires based on tire type, a floor at which the TPMS warning would be triggered regardless of the manufacturer’s recommended pressure level.

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FOR USE BY PURGEN98 DEALERS ONLY Page 132 of 168 Figure 1: Tire Pressure Monitoring Systems

NHTSA also uses public information and educational campaigns to convey the importance of maintaining properly inflated tires. In 2005, for example, NHTSA issued brochures for a campaign it called “What’s Your PSI?” to encourage the public to check its tires regularly for proper inflation. NHTSA partnered with both the Rubber Manufacturers Association (RMA) and the American Automobile Association’s Motor Clubs, which distributed the brochures to members. Additionally, NHTSA, in conjunction with RMA, sponsors a “Tire Safety Week” during the last week of April each year.13 A NHTSA official told us that the agency plans to have public information campaigns about TPMS before the requirement becomes fully implemented for the 2008 model year.

GSA, which leased about 185,000 vehicles to federal agencies in fiscal year 2005,14 provides ongoing guidance to federal fleet managers on the maintenance of their

13RMA also has a public awareness effort, referred to as “Be Tire Smart,” that includes brochures aimed at informing the public of the need to properly maintain tire pressure. 14According to GSA’s Federal Fleet Report Fiscal Year 2005, the federal fleet included more than 632,000 vehicles. GSA leases 29 percent of these vehicles to agencies, 69 percent are purchased by the agencies, and 2 percent are leased from commercial sources.

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FOR USE BY PURGEN98 DEALERS ONLY Page 133 of 168 vehicles, including suggestions for maintaining proper tire pressure.15 For example, in response to the President’s 2005 directive to conserve natural gas, electricity, gasoline, and diesel fuel after Hurricanes Katrina and Rita, GSA sent fleet customers fuel conservation tips that contained information on proper tire inflation. GSA does not operate maintenance shops of its own but instead tracks fleet vehicle maintenance. GSA also notifies lessees of upcoming or past-due maintenance requirements and follows up to assure work is completed. Agencies that lease vehicles from GSA are responsible for procuring maintenance and repair services from private vendors. They are also responsible for assuring proper tire inflation. According to GSA’s Director of Fleet Operations, GSA’s fees for leased vehicles are determined by a combination of a monthly rate and a mileage rate.16 In addition, GSA funds fuel and maintenance costs. However, if a vehicle’s tires wear out sooner than expected, or are not maintained appropriately, GSA charges the customer agency for the increased costs.

The Department of Defense, with one of the largest fleets of GSA-leased vehicles, instituted a policy requiring users to maintain tires at the maximum pressure recommended by the vehicles’ manufacturers.17 Various DOD departments implemented this policy by requiring periodic and consistent tire inspections. For example, the Air Force requires vehicle operators to document tire pressure inspections each month at a minimum. The Navy requires vehicle operators to check tire pressure before using a vehicle and conduct preventive maintenance on vehicles, including tire pressure and tread checks, at least every 3 months, 5,000 miles, or 200 hours of use. Similarly, the Defense Logistics Agency requires vehicle operators to check vehicle equipment, including tire pressure daily.

Technologies Used to Reduce Tire Underinflation May Promote Better Fuel Economy and Safer Vehicle Handling

Several technologies are currently available to reduce tire underinflation, including tire pressure gauges, TPMS, compressed air, nitrogen, and improved tire materials. Drivers of passenger cars, as well as drivers of light and heavy trucks, use tire pressure gauges to check tire pressure. TPMS equipment is programmed to alert drivers of passenger vehicles when tire pressure falls 25 percent below the level recommended by vehicle manufacturers or a minimum pressure set by regulation, whichever is higher. Compressed air and nitrogen are available to the public to inflate tires, and newer materials for tire innerliners and designs for truck tires will maintain tire pressure levels longer. In addition, tire pressure management systems

15GSA sells and leases passenger cars and vans; light, medium, and heavy trucks; and buses and emergency vehicles to customer agencies. 16All of GSA Fleet’s preventive maintenance instructions include checking tire pressure as part of the preventive maintenance service. Additionally, GSA Fleet places in the glove box of every vehicle it leases to customer agencies a pamphlet entitled A Guide to Your GSA Fleet Vehicle. The pamphlet informs vehicle operators about proper tire care to include the importance of checking air pressure regularly. The pamphlet also describes for operators how to determine proper tire pressure for a vehicle. 17DOD, Management Acquisition and Use of Motor Vehicles, Section C12.2.5.5, from DOD 4500.36-R. (Washington, D.C., 1996).

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FOR USE BY PURGEN98 DEALERS ONLY Page 134 of 168 and central inflation systems are available to address tire underinflation on heavy trucks. TPMS equipment also alerts drivers of heavy trucks when tire pressure falls below a certain level. The basic features of each type of technology are discussed below. If used properly, all of the features have the potential to increase fuel economy and enhance vehicle safety.

Tire Pressure Gauges

The federal government and industry recommend that drivers of passenger vehicles use a tire pressure gauge to check their tire pressure at least once a month, when tires are cold, and inflate them to the pressure recommended by the vehicle manufacturer.18 (See fig. 2.) Tire industry officials indicated that large trucking fleets recognize this as a good practice, since tires and their maintenance represent a portion of their operating costs, and generally monitor their vehicles’ tire pressure on a more frequent basis.19 The American Trucking Association’s Technology and Maintenance Council also recommends that its members use quality truck tire pressure gauges and check them weekly against a “master gauge.”

18The vehicle manufacturer’s recommended pressure is posted inside the vehicle on the placard. 19Other costs are labor and fuel.

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FOR USE BY PURGEN98 DEALERS ONLY Page 135 of 168 Figure 2: Two Types of Tire Pressure Gauges

Source: GAO.

TPMS

TPMS technology will be available on all passenger vehicles starting with the 2008 model year. According to DOT, the TPMS final rule’s phase-in has increased the prevalence of TPMS in the new vehicle fleet. Under the April 8, 2005 final rule,

• 20 percent of a vehicle manufacturer’s passenger vehicles and light trucks are required to comply with the standard from October 5, 2005, to August 31, 2006;

• 70 percent are required to comply from September 1, 2006, to August 31, 2007; and

• all of these vehicles must comply by September 1, 2007.

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FOR USE BY PURGEN98 DEALERS ONLY Page 136 of 168

Although TPMS is now available on certain luxury cars and is available as optional equipment on large trucks, questions remain about how TPMS will operate on most vehicles. For example, NHTSA does not require that the TPMS identify the specific underinflated tire and only requires that it work with the tires originally installed by the vehicle manufacturer. NHTSA requires the TPMS used on passenger cars and light trucks to include a malfunction indicator lamp to alert the driver of the presence of incompatible replacement tires on the vehicle and when the TPMS is unable to detect low tire pressure for other reasons.

Compressed Air

Compressed air, which is a combination of mostly nitrogen and oxygen,20 is customarily used to inflate tires and is widely available at facilities such as service stations and retail tire outlets. In addition, the cost of using compressed air is usually free or relatively inexpensive. According to some industry officials, compressed air permeates tires more quickly than other products such as nitrogen. However, tire researchers and others indicate that either product is effective if drivers check their tires regularly and reinflate when necessary.

Nitrogen

Some industry officials promote the use of nitrogen to inflate vehicle tires. Nitrogen permeates the rubber used in tires more slowly than air. Studies have shown that nitrogen retains tire pressure longer and slows tire degradation.21 However, according to researchers, no studies have been conducted that show the results of nitrogen use on safety and fuel efficiency under normal driving conditions.

Currently, studies are being conducted on the use of nitrogen to inflate tires. A Canadian nitrogen manufacturer is planning to submit a report to Transport Canada, the Canadian government’s transportation ministry, in early 2007 on the effect of nitrogen inflation on fuel efficiency and costs in long-haul trucks.22 It is unclear when the report will be made available to the public. NHTSA is conducting two laboratory studies on this topic for passenger and light truck tires—one on the effects of nitrogen inflation on the rate of loss of inflation pressure, with testing expected to be complete in April 2007, and another on the effects of nitrogen inflation on tire aging. NHTSA expects to complete testing on the tire aging study in March 2007, with public reports on the two studies to follow.

20Air is composed of 78 percent nitrogen and 21 percent oxygen. Argon and carbon dioxide make up the remaining 1 percent. 21For information on tire pressure retention, see Guy Walenga, Bridgestone/Firestone, Nitrogen Inflation for Truck Tires (presented at Clemson Tire Conference, Mar. 11, 2004). For information on tire degradation, see Uday Karmaker, Akron Rubber Development Laboratory, Inc., Harold Herzlich, Herzlich Consulting, Inc., Effect of Nitrogen Purity on the Oxidation of Belt Coat Compound (presented at International Tire Exhibition and Conference 2006, Akron, Ohio); and John M. Baldwin, David R. Bauer, Kevin, R. Ellwood, Ford Motor Co., Effects of Nitrogen Inflation on Tire Aging and Performance (conference paper, May 2004). 22The study was originally undertaken to evaluate technologies to reduce greenhouse gases.

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FOR USE BY PURGEN98 DEALERS ONLY Page 137 of 168 Two challenges affecting the widespread use of nitrogen in passenger cars and light truck tires include the lack of infrastructure that would make it readily available to consumers and the cost of filling tires. According to federal and industry officials, researchers, and public safety advocates, most service stations and tire retailers do not have nitrogen pumps or generators. Retailers such as Costco and some Sam’s Club locations are exceptions and currently offer nitrogen, at no cost, to their members when they purchase tires. Since other retailers offer nitrogen on a more limited basis nationwide, and the cost of using it varies depending on the retailer or the location, we could not reliably determine the average cost of filling a tire. Industry officials indicated that some retailers may purge air from a vehicle’s tires and replace it with nitrogen at no cost while others may charge prices ranging from $20 to $79 per vehicle.23

Tire Innerliners

Tire manufacturers can select from a variety of materials to make tire innerliners— the coating laminated to the inside of tires. The type of material selected determines the amount of air and water vapor that permeates a tire and causes it to deflate and degrade. Currently, the tires most often available to consumers include innerliners that are made from varying blends of synthetic rubber polymers (known as halobutyls) and other types of rubber. Tire researchers and experts have shown that innerliners made from high ratios of bromobutyl, one type of halobutyl, are the least permeable to air and water vapor and best able to retain pressure. However, innerliners made from high ratios of this material are more expensive than those made with high ratios of natural and synthetic rubbers and, according to researchers, are more likely found in original equipment tires than replacement tires.

Truck Tire Design and Inflation Systems

Improvements in heavy truck tire testing and central inflation systems have the potential to reduce tire underinflation and increase fuel economy. Single-wide tires have replaced dual tires on some large trucks and tractor trailers. According to the Environmental Protection Agency (EPA), single-wide tires could improve fuel economy by up to 4 percent because they have less rolling resistance and weight. According to DOT, single-wide tires also reduce by half the number of points to check and tires to inflate, significantly reducing the time needed to check tire pressure on a tractor-trailer combination vehicle. Tire pressure monitoring systems can provide an early warning of air pressure loss before a tire sustains damage. Single-wide tires also present several disadvantages that involve transition costs for fleets and their potential damage to highway pavement (see encl. III). In addition, central inflation systems on trucks can continually monitor and adjust the amount of inflation pressure in tires while the vehicle is in motion. According to officials from the EPA and the Federal Motor Carrier Safety Administration, these systems could also improve fuel economy. (See encl. III for further discussion of these technologies.)

23Because of the relative lack of studies showing the impact of nitrogen on fuel economy, and the varying costs cited for inflating tires with nitrogen, we did not determine the extent to which the increased cost for inflating tires may be offset by lower fuel costs and a less frequent need to purchase replacement tires.

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FOR USE BY PURGEN98 DEALERS ONLY Page 138 of 168 Agency Comments

We provided copies of a draft of this report to the Departments of Transportation, Defense, and Energy; the General Services Administration; and the Environmental Protection Agency. Their technical comments have been incorporated into the report, as appropriate.

------

As agreed with your office, unless you publicly announce the contents of this report earlier, we plan no further distribution until 30 days from the report date. At that time, we will send copies to other interested congressional committees. We will also make copies available to others upon request. In addition, the report will be available at no charge on GAO’s Web site at http://www.gao.gov.

If you or your staff have any questions about this report, please contact me at (202) 512-6570 or [email protected]. Contact points for our Offices of Congressional Relations and Public Affairs may be found on the last page of this report. Individuals making key contributions to this report are listed in enclosure IV.

Sincerely yours,

Katherine A. Siggerud Director, Physical Infrastructure Issues

Enclosures

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FOR USE BY PURGEN98 DEALERS ONLY Page 139 of 168 Enclosure I: Scope and Methodology

We obtained information on a variety of issues involving passenger and truck tires in the United States by interviewing officials, and examining the documents they provided, with the federal agencies, tire and automotive industries, businesses, and public safety advocacy groups shown in table 1. Officials with the Department of Transportation’s (DOT) National Highway Traffic Safety Administration (NHTSA) and Federal Motor Carrier Safety Administration (FMCSA) provided documents on their public information efforts to encourage the public to regularly check their tires for proper inflation; data on accidents and fatalities caused by underinflated tires; analyses developed for the tire pressure monitoring system (TPMS) regulations; and information about ongoing studies on tires. Officials with the public safety advocacy groups and some industries provided their views on TPMS regulations. In addition, we reviewed NHTSA’s survey of tire pressures in passenger vehicles and studies on tire safety. The General Services Administration provided information on its vehicle leasing program, including details on maintenance as a factor in agencies’ lease rates. We obtained information on the role that civilian and military Department of Defense employees have in maintaining appropriate tire pressure levels for vehicles in its fleet. The Department of Energy, Environmental Protection Agency, National Academy of Sciences’ Transportation Research Board, Akron Rubber Development Laboratory, and the business groups provided information and data on using compressed air and nitrogen to inflate tires, and the impact on safety and fuel economy of each product. We also obtained information from industry associations on their initiatives to alert the public on tire inflation.

Industry officials provided information on the materials used to make and inflate tires and the impact that a TPMS will have on tires. The public advocacy groups provided information on the impact that a TPMS may have on tire safety.

We received information from some organizations listed in table 1 on the technologies currently available to reduce underinflation and their implications for fuel economy and safety. In addition, we interviewed manufacturers (e.g., Ingersoll- Rand) that produce nitrogen generation equipment for tire inflation to determine why they believe it is a better product for inflating tires, as well as retailers (e.g., Costco) that offer both nitrogen and compressed air to consumers. We also obtained comments from officials we interviewed on the reliability, safety, cost effectiveness, and fuel efficiency of compressed air and nitrogen to inflate tires. We performed our work from July 2006 through December 2006 in accordance with generally accepted government auditing standards.

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FOR USE BY PURGEN98 DEALERS ONLY Page 140 of 168

Table 1: Organizations Contacted during Our Review

Federal organizations Department of Transportation (NHTSA and FMCSA) Department of Defense Department of Energy General Services Administration Environmental Protection Agency Industry associations Rubber Manufacturers Associationa American Trucking Association American Automobile Association Alliance of Automobile Manufacturersb Tire Industry Association Tire Retread Information Bureau Businesses Ford Motor Company Roush Racing NASCAR American Airlines Akron Rubber Development Laboratory Ingersoll-Rand Branick Industries Parker Hannifin Schrader-Bridgeport EnTire Solutions Costco Wal-Mart Discount Tire Company Tire Kingdom Public advocacy organizations Center for Auto Safety Advocates for Highway and Auto Safety Public Citizen Source: GAO. a Representatives from Bridgestone, Continental, Goodyear, Michelin, and Pirelli tire companies participated in this meeting. bRepresentatives from General Motors and Daimler Chrysler participated in this meeting.

Page 13 GAO-07-246R Underinflated Tires

FOR USE BY PURGEN98 DEALERS ONLY Page 141 of 168 Enclosure II: Tire Pressure Monitoring Systems

NHTSA requires all new 2008 model year passenger cars and light trucks to have a tire pressure monitoring system (TPMS) to alert drivers when the pressure in one or more tires falls 25 percent below the vehicle manufacturer’s recommended inflation pressure or a minimum activation pressure specified by NHTSA, whichever is higher.24 NHTSA also requires the TPMS to include a malfunction indicator that alerts drivers when the TPMS is not functioning because of either a system failure or the placement of incompatible replacement tires on the vehicles.

Industry developed two types of TPMS—direct and indirect. A direct TPMS uses an electronic device mounted either on the valve stem or the inside of a wheel to read inflation pressure. It sends a wireless signal about a tire’s inflation level to a receiving unit that alerts the driver through a warning light on the dashboard if tire pressure falls below a certain threshold.25 An indirect TPMS uses a vehicle’s existing anti-lock braking system equipment to monitor the rotational speeds of the wheels. When it detects a difference in rotational speed in one wheel compared with the others, the system infers that a tire is underinflated and alerts the driver through a visual alarm.

Industry and public safety advocacy groups have expressed concern about the capabilities of TPMS as it relates to NHTSA’s requirements. For example, a tire industry official said that if replacement tires not compatible with the TPMS are installed, NHTSA regulations require that the malfunction indicator lamp illuminate to alert the driver that the TPMS cannot detect underinflation.26 In such cases, the owner would have to replace the new equipment for tires or wheels that are compatible with the TPMS. According to DOT, however, available data suggest that only a very small number of replacement tires are likely to generate problems for TPMS, although it has not been possible to identify problematic tires based on size or construction characteristics. Although DOT officials claim that vehicle manufacturers report few warranty claims based on instances of replacement tires being incompatible with a TPMS, we think that conclusions about this area should wait until after 2008, when more vehicles are equipped with a TPMS.

At the time of our review, no indirect TPMS has been marketed that meets NHTSA’s requirement to identify one to four underinflated tires at a time. Further, the indirect TPMS cannot detect underinflation when all four tires are equally underinflated. An indirect TPMS is considered the least expensive option, however, because it requires less additional hardware on vehicles equipped with anti-lock brakes. As previously noted, NHTSA’s current rule is in litigation. In accordance with our policy, we neither included in our objectives nor addressed matters in litigation.

24FMVSS No. 138. 70 Fed. Reg. 18136 (April 5, 2005); see, also, 70 Fed. Reg. 54079 (Sept. 7, 2005), “Tire Pressure Monitoring Systems.” 25Although NHTSA requires that the alert be triggered when pressure falls 25 percent below the vehicle manufacturer’s recommended level, some TPMS, depending on the manufacturer, will trigger alerts earlier. 26NHTSA requires that original equipment manufacturers certify TPMS on the tires installed on the vehicle at the time of the initial vehicle sale.

Page 14 GAO-07-246R Underinflated Tires

FOR USE BY PURGEN98 DEALERS ONLY Page 142 of 168 Enclosure III: New Tire Designs and Technologies for Heavy Trucks Offer Enhanced Safety and Improved Fuel Economy

Several recent innovations in truck tire and wheel technology are designed to enhance fuel economy and also offer safety benefits. For example, single-wide tires27 are designed to replace traditional dual-mounted tires on trucks—one single-wide tire is mounted on each side of an axle. Single-wide tires can be used for all tractor and trailer tire positions except for the steer tires at the front of the tractor. Using single- wide tires, a traditional 18-wheel tractor-trailer, with 2 steer tires, 4 pairs of drive tires, and 4 pairs of trailer tires, would have a total of only 10 tires—2 steer tires, 4 drive tires, and 4 trailer tires. According to the EPA’s SmartWay Transport Partnership,28 the reduced rolling resistance and weight of the tires and wheels could improve fuel economy by up to 4 percent.29 According to DOT, single-wide tires also reduce by half the number of points to check and tires to inflate, significantly reducing the time needed to check tire pressure on a tractor-trailer combination vehicle. Similarly, the American Trucking Association (ATA) noted that single-wide tires effectively eliminate the problem of checking inflation pressure on the inner dual-mounted tire. Additionally, tire pressure monitoring systems can provide an early warning of air pressure loss before a tire sustains damage.

ATA noted, however, that single-wide tires present several disadvantages. For example, transition costs might pose a challenge, since fleets would have to maintain two sets of wheel hardware until the entire fleet was converted. Another disadvantage is the potential damage to pavement. According to ATA and Virginia Tech’s Transportation Institute, the first generation of single-wide tires damaged pavement at a greater rate than dual-mounted tires.30 However, as the design of single-wide tires has evolved, the tires have become increasingly wider. According to a FMCSA official, wider tires distribute the load over a greater area, reducing the impact on the pavement. These experts also say that potential for pavement damage from the newest generation of single-wide tires is comparable with conventional dual- mounted tires. A potential disadvantage, according to DOT, involves the safety of the truck if one of the single-wide tires fails. In contrast, when one of a pair of dual- mounted tires fails, there is still another tire available.

Central inflation systems are another technology for trucks to reduce underinflation. These systems can monitor and continually adjust the inflation pressure in tires, even while the truck is in motion. Two main types of systems are currently available. One system uses the truck’s existing air-brake compressor to supply air to tires. Another uses self-contained compressors on each hub that generate compressed air through

27Also known as “super-singles” or “wide-base” tires, single-wide tires have been used on trucks in Europe and Canada since the early 1980s. A distinction should be made between first generation “super-single” tires, which were introduced in the 1980s and “new generation” super-singles” tires. 28EPA’s SmartWay Transport Partnership is a voluntary collaboration between U.S. EPA and the freight industry designed to increase energy efficiency while significantly reducing greenhouse gases and air pollution. 29This assumes single-wide tires are mounted using weight-saving aluminum rims on all applicable axles of the tractor and the trailer. 30I. L. Al-Qadi, M. Elseifi, and P.J. Yoo, Virginia Tech Transportation Institute, Pavement Damage Due to Different Tires and Vehicle Configurations (Blacksburg, Virginia, May 2004); and Jim Tipka, American Trucking Institute, New Generation Wide Based Single Tires (June 2006).

Page 15 GAO-07-246R Underinflated Tires

FOR USE BY PURGEN98 DEALERS ONLY Page 143 of 168 the rolling motion of the wheels. According to FMCSA, central inflation systems could offer significant savings to fleet operators by improving fuel economy and safety. According to EPA’s SmartWay Transport Partnership, these systems could annually save long-haul trucks up to $200 in tire maintenance costs, and $170 in fuel costs per truck. However, these systems also present several disadvantages. For example, according to an ATA official, systems operating from the air-brake compressor involve an extensive array of tubing and valves, increasing the potential for leaks.

Page 16 GAO-07-246R Underinflated Tires

FOR USE BY PURGEN98 DEALERS ONLY Page 144 of 168 Enclosure IV: GAO Contact and Staff Acknowledgments

GAO Contact

Katherine Siggerud, (202) 512-6570 or [email protected]

Staff Acknowledgments

In addition to the contact named above, Nabajyoti Barkakati, Lindsay Bach, Colin Falon, Jay Cherlow, Lynn Filla-Clark, H. Brandon Haller, Phillis Riley, Karla Springer, Don Watson, and Mindi Weisenbloom made key contributions to this report.

(542094)

Page 17 GAO-07-246R Underinflated Tires

FOR USE BY PURGEN98 DEALERS ONLY Page 145 of 168

This is a work of the U.S. government and is not subject to copyright protection in the United States. It may be reproduced and distributed in its entirety without further permission from GAO. However, because this work may contain copyrighted images or other material, permission from the copyright holder may be necessary if you wish to reproduce this material separately.

FOR USE BY PURGEN98 DEALERS ONLY Page 146 of 168

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PRINTED ON RECYCLED PAPER

FOR USE BY PURGEN98 DEALERS ONLY Page 147 of 168

February 2006 FLM Dealers & Nitrogen

Claimed Nitrogen benefit by Ford Engineering:

"In certain climates and applications, Nitrogen may enhance the ability of the tire to maintain inflation pressure over time."

Dealers MUST only claim this benefit when selling and in advertising brochures & promotions. All other claimed benefits will NOT be backed by Ford Motor Company / Rotunda.

At this time Ford Rotunda is only providing Nitrogen generators to offer Nitrogen in new tire sales. The tire inflation procedure below must be followed to achieve the greater than 95% Nitrogen level recommended by Ford engineering.

At this time offering Nitrogen as an air replacement in existing tires will not be backed by Ford engineering / Rotunda. Current evaluations of automated air purging equipment have not proven effective and are still under investigation.

Dealers must also inform the consumer to check their tire pressure at least once a month or before long trips and refer them to their Owner Guide "Inflating Your Tires" section.

Dealers should be aware and inform the consumer that Nitrogen will have no effect on pressure loss due to leakage around the rim flange seal of the tire to rim and also the valve stem seal to wheel or pressure loss through the valve stem itself.

FLM Dealers – Nitrogen.doc

FOR USE BY PURGEN98 DEALERS ONLY Page 148 of 168

February 2006

Ford New Tire Nitrogen Fill Procedure

Following this procedure will insure greater than 95% Nitrogen purity.

1. Insure tire changer air supply is connected to the outlet of the Nitrogen generator. 2. Using the manufacturer's procedure and safety precautions install the tire on the rim. 3. With valve core removed seat the tire bead using the bead blaster in conjunction with the air hose from the tire changer. 4. Inflate tire to 5 PSI over vehicle tire pressure setting. 5. Remove air supply hose and let air purge out to equal ambient air pressure. 6. Refill tire using air hose from tire changer to 5 psi over vehicle tire pressure setting, remove air supply hose, install valve core and torque to 3-5 in. lbs. 7. Adjust to vehicle tire pressure setting and install green valve stem cap.

Questions pertaining to this procedure should be directed to Dave Werthmann 313-317-9117 or [email protected].

FLM Dealers – Nitrogen.doc

FOR USE BY PURGEN98 DEALERS ONLY Page 149 of 168

February 2006

Ford Rotunda Suppliers & Nitrogen

Claimed Nitrogen benefit by Ford Engineering:

"In certain climates and applications, Nitrogen may enhance the ability of the tire to maintain inflation pressure over time."

Above and beyond normal Rotunda requirements suppliers MUST adhere to and perform the following:

• Only claim benefit indicated when selling and in advertising brochures & promotions. All other claimed benefits will NOT be backed by Ford Motor Company / Rotunda. • Include a copy of "FLM Dealers – Nitrogen" with all equipment sold.

Questions pertaining to this should be directed to Dave Werthmann 313-317-9117 or [email protected].

FLM Dealers – Nitrogen.doc

FOR USE BY PURGEN98 DEALERS ONLY Page 150 of 168 DEC 31,2005 10:35A CAL PIPER 9543643198 Page 1 http:llsenrice.gm.c0mlsewletslBI0bSht~746670&pubid... 12/31/2005

Dacumilnt IP# 1746670 <- Back I Forward -> 1 Feedback 1 Print 1 2006 Chevralet WWR

Info - Use of Nitrogen Gas in Tires #05-

Use of Nitrogen Gas in Tires

All 2008 and Prior GM Passenger Cars and LightlMedlum Duty Trucks (including Saturn)

2003-2006 HUMMER I42

2008 HUMMER H3

2005-2006 Saab 9-7X

GM's Position on the Use of Nitrogen Gas in Tires

General Motors doer not oppose the use of purlfied nitrogen as an inflation gas for tlres. We expect the theoretical bendtr to be reduced in practical use due to the lack af an existlng infrastructure ta continuously facilltats inflating tires wlth nearly pure nitrogen. Even occasional inflation with compressed atmospheric air wlll negate many of the theoretical benefits. Glven those thmaretical benefits, practical Ilmltatlorrs, and the robust design of OM original equipment tPC tlres, the reallxed benefits to our customer of Inflating thelr tires with purified nitrogen are expected to be minimal.

The Promise of Nitrogen: Under (;ontrolled Cahditions

Recently, nitrogen gas (for use In Inflating tires) has become available ta the general consumer through some retailers. The use of nitrogen gas to inflate tires is a technol~gyused In automobile raclrrg. The following benefits under controlled condltlans are attributed ta nitrogen gar and its unique properties:

A reduction in the expected loss of Tire Pressure aver tlme. A reductlan In the variance of Tire Pressures with temperature changes due to reduction of water vapor cancmtration.

Slebrvlee Information Page I of 3

FOR USE BY PURGEN98 DEALERS ONLY Page 151 of 168 DEC 31,2005 10:35A CAL PIPER 9543643198 Page 2 http:ll~enricr.gm.c0mIsewletsIBI0b8html?htmlFl746670&pubid... 1213112005

+ A reducti~nof lorng term rubber degradatian due to a decrease in oxygen concentrations.

Important: Thsss are obtainable performance improvements when relatively pure nitrogen gas is used to inflate tires under controlled conditions.

The Promise of Nitrogen: Real World Use

Nitrogen inflation can provide same benefit by reducing gas migration (ptesvure loss) at the molecular level through the tlre structum. NHTSA (Natianal Highway traffic Safety Administration) has stated that the inftatian pressure lass af tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "sesplng" through the tlm caring. The actual obtainable benefits of nltrogan varies, based on the physical construction and the materials used In the manufacturing of the tlre being inflated.

Another potential benefit of nitrogen Is the reduced oxidation of tire components. Research has dernslrstrated that oxygen cvnsumed In the vxidatlan process of the tire primarily comes from the inflation media. Therefare, it is reasonable to assume that axidation of tire components can be reduced ifthe tlre is inflated with pure nitrogen. However, arrly very small arnaunts of axygen are rtsqulred to bagin the normal oxldation process. Even slight contamination of the tire inflatian gas wlth compressed atrnosphsrlc air during normal inflation pressure maintenance, may negate the benmts of using nitrogen.

GM Tlre Quality, Technology and Focus of Importance

Since 1972, General Motors has designed tlres under the TPC (Tire Performance Crlterla) specification system, which Includes specific requirements that ensure robust tire performance under normal usage. General Motam works with tire suppliers to design and manufacture original equlprnent tires for CM vehlclss. The GM TPC addfesses required perfarmancr with respect to both inflation pmasure vetention, and endurance properties for orlainal equipment tires. The inflation pressure retentIan requirements address availablllty of axygen and axidatlon conclmms, while endurance requirmments ensure the mechanical structure af the tire has smcient strength. This combination has provided our customers with tires that maintain their structural integrlty throughout their useful treadlife under normal operating conditions.

Regardtess of the inflation rnedla for tires (atmospheric air or nitrogen), inflation prosure maintenan~eof tires is critieal for overall tire, and ultlmately, vehicle

Service Information Page 2 of 3

FOR USE BY PURGEN98 DEALERS ONLY Page 152 of 168 DEC 31,2005 10:36A CAL PIPER 9543643198 Page 3 http:llsenlce.gm.camlaewletdBlobShtml?8htmIF11~=174867O&publd... 42/31120Q5

psrfamrance. Maintaining the correct inflation pressure allows the tire to perform as intended by the vehlcls manufacturer in many areas, irkeluding comfort, fuel economy, stopping distance, cornering, traction, treadwear, and noise. Since the load canylng capabltlty of a tlra is related to inflation pressure, proper inflation pressure maintenance is necessary for the tlre ta support the load imposed by the vehicle without ex~esrlvestructural degradation.

Important: Regardless of the infiation media for tires (atmospheric air or nitrogen) inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance.

OM bull+tlnr anIntmhdd far uas by pmlserlonal t~hnlclana,NOT e wd~-lt-y~urwhr. They rrr wrlttrn to lnfonn these tmchnlclers of conditions thnt may occur on some WE SUPPORT In vrhleior, ar to pmvide informmtion thst could rsrlst the pmper mewice d a v*)ricle. VOLUNTARY Properly trnlnmd t-hnlclans hrvs th+ +qulpmont, toola, snfety in+truelisnr, mad know-how to do a job propstly and *elely. If B condltlon Is described, Do NOT assume that tha TECHNICIAN bulletin rrpplios ta your vshicls, er that your vehlel+ All have Chat eomdltlon. 3a+ yrur liM GERTlFlcATION danler for Infarmnllan an WkMhbr yeut WhlCle md+y benefit from the Informatlm.

Document Ib# 1746670 2006 Chevrolet HHR

Service Infomation Page 3 of 3

FOR USE BY PURGEN98 DEALERS ONLY Page 153 of 168 Page 1 of 3

Robin Pearl

From: [email protected] Sent: Tuesday, October 18, 2005 4:57 PM To: Robin Pearl Cc: [email protected]; [email protected]; [email protected]; [email protected] Subject: RE: Purigen 98 Letter to Dieter Zetsche

Mr. Pearl,

As I stated in my previous e-mail, tire manufacturers are responsible for the warranty on tires - and DCC would follow whatever instructions that the tire manufacturers are giving to the dealers and the after market tire supply chain. Having said that, I have attached below a Goodyear product service bulletin that indicates a favorable response to nitrogen filled tires. Since Goodyear represents over 70% of our OE tire supply, we would follow the lead that Goodyear has taken. Stated another way, DCC has no issues with nitrogen filled tires as long as the tire manufacturer indicates a favorable or neutral position and that warranties are unaffected. Is there anything else that you require at this time?

THE GOODYEAR TIRE & RUBBER COMPANY

PRODUCT SERVICE DEPARTMENT Page 1 of 1

Nitrogen gas, as an inflation alternative to air, is becoming more prevalent in the market place and is being marketed as a benefit to the standard practice of using air to inflate tires.

Over a period of time both oxygen and nitrogen are able to penetrate through tire casings. However, oxygen molecules and nitrogen molecules are different sizes with oxygen being a smaller molecule than nitrogen. The size difference in the molecules allows the smaller oxygen molecule to permeate through the rubber at a more rapid rate.

Goodyear supports the use of nitrogen, as an inflation gas, in all Goodyear, Dunlop, Kelly, Associate Brand and Private Brand products, based on the ability for a tire to retain pressure for a longer period of time. The use of nitrogen will not affect the tire warranty.

Please be advised that even with the use of nitrogen as an inflation gas, regular inflation pressure checks are highly recommended.

Bill Beistline Director - Chassis Components Procurement [email protected] Phone : 248-576-2700 Cell: 248-495-5095

1/6/2006FOR USE BY PURGEN98 DEALERS ONLY Page 154 of 168 Page 2 of 3

"Robin Pearl" To cc , , 10/17/2005 10:13 PM , Subject RE: Purigen 98 Letter to Dieter Zetsche

Dear Mr. Beistline:

Have you been able to further research my question on nitrogen tire inflation. I look forward to your reply. Thank You, Robin Pearl President

5289 NW 108 Avenue Sunrise, Florida 33351 (954) 741-4278 (954) 337-4614 fax [email protected]

From: [email protected] [mailto:[email protected]] Sent: Friday, August 26, 2005 4:57 PM To: [email protected] Cc: [email protected]; [email protected]; [email protected]; [email protected] Subject: Purigen 98 Letter to Dieter Zetsche

Mr. Pearl,

1/6/2006FOR USE BY PURGEN98 DEALERS ONLY Page 155 of 168 Page 3 of 3

I am in receipt of your letter to Dr. Zetsche dated August 5, 2005 regarding the request for a position from DaimlerChrysler on nitrogen inflated tires. I am the Director of Chassis Purchasing responsible for the procurement of all tire requirements for DCC. In relation to your question, I am writing to inform you that DCC at this moment does not have an answer to the question that you posed - specifically - a position relative to nitrogen filled tires. Tires are unusual for us in that the tire manufacturer is responsible for warranty - and we would typically defer an answer on your question to them. Having said that, we will be having discussions both internally and with our current supplier tire manufacturers to understand the effects of nitrogen filled tires. I am hoping that we can come to a conclusion in the next few weeks to give you a more formal response. In the mean time, feel free to contact me if you have other questions.

Bill Beistline Director - Chassis Components Procurement DailmerChrysler Corporation [email protected] Phone : 248-576-2700 Cell: 248-495-5095

1/6/2006FOR USE BY PURGEN98 DEALERS ONLY Page 156 of 168

Paper No19B

EFFECT OF NITROGEN PURITY ON THE OXIDATION OF BELT COAT COMPOUND

By Uday Karmarkar* Akron Rubber Development Laboratory, Inc. 2887 Gilchrist Rd. Akron, Ohio 44305 [email protected]

Harold Herzlich Herzlich Consulting Inc 8908 Desert mound Drive Las Vegas, NV 89134 [email protected]

Presented at a meeting of the International Tire Exhibition and Conference 2006 Akron, Ohio

* Speaker

FOR USE BY PURGEN98 DEALERS ONLY Page 157 of 168 Abstract Nitrogen filling in tires has been carried out to reduce pressure loss and moisture in tires as well as to reduce the oxidative component aging process in tires. This study aims to develop the understanding of the effect of nitrogen purity on tire component oxidation using an efficient design of experiment technique. Traditional tensile/elongation testing technique has been carried out on steel belt coat compounds in tire reactors to study the relative effect of nitrogen purity compared to time, temperature, and antioxidant levels.

Introduction Nitrogen tire inflation has been widely used as a fill gas for race tires. Air is typically used as a fill gas for most other applications such as the ubiquitous passenger, light and medium truck automotive population.

Until recently, a safe, viable technology and infrastructure that could economically supply high purity nitrogen tire fill gas to the general public was not available. With the advent of properly constructed generators with cost effective diffusion separation membranes, a high purity nitrogen inflation infrastructure is being developed. Air is a mixture of 3 important components that affect the tire performance, approximately 80% nitrogen, 20% oxygen and highly variable moisture levels. The oxygen component of the fill gas is the active component that determines the oxidative weakening of the tire component. The oxidative deterioration of elastomers used in tires has been described in the literature and accepted by the scientific community.

Tire pressure monitoring systems will soon be mandatory on all vehicles. Contamination or degradation of these systems would be minimized by high purity nitrogen inflation. Nitrogen molecules migrate through rubber more slowly than oxygen resulting in better retention of inflation pressure. Moisture inside a tire causes inflation pressure anomalies and possible deterioration of the wheels and reinforcing textiles. Oil from the air compressor is also undesirable.

This study focuses on how changes in the nitrogen/oxygen ratio of the fill gas affects the aging characteristics of a typical belt coat rubber compound. Purity of nitrogen in the tire is a function of the initial generator purity, target pressure of the tire and the number and method of refills of the cavity gas. For a tire with a target pressure of 32 psig, filling with a nitrogen generator of 98 percent nitrogen purity output will generate a final nitrogen purity of 92, 96 and 97 percent with each successive complete refill. Similarly, for a nitrogen generator of 95 percent purity output, we achieve 90, 94, and 95 percent target purity with each successive complete refill. It has been shown that property changes with greater than 95% purity in a tire are within the error limits inherent in tire cure variations.

The research presented in this paper will concentrate on providing data on rubber degradation and extent of oxidative aging in relation to the purity of the nitrogen. This information is applicable to tire belt edge compounds as well as to rubber

FOR USE BY PURGEN98 DEALERS ONLY Page 158 of 168 products used in an oxidative environment such as gas powered machine tools. The relative importance of oxygen partial pressure, antioxidant level, time and temperature will be evaluated using a novel design of experiments. The correlation between crack growth at belt edge, oxidation and whole tire durability will be established in a subsequent paper utilizing the tire reactors from this statistical design of experiments. Effect of nitrogen purity on whole tire crack development at belt edge and tire durability will be studied in a future paper.

Experimental

Design of Experiments A statistical design of experiments was setup using JMP Statistical Discovery Software Release: 5.0.1.2. Four inputs were studied, temperature, time, partial pressure of oxygen, antioxidant level. A full factorial 2x2x2x2 design of experiments was setup with a single center point. The data from the experiments is plugged into the same JMP program to handle and model the inputs with the output generated and illustrate the influence of the effects on the output. The compounded slabs were aged in the inner cavity of the tire. This allows for the accurate measurement and monitoring of the partial pressure of the oxygen in the vicinity of the samples as well as accurate aging of the tire reactors in calibrated ovens for different times. The partial pressure was maintained within 5 percent of the original set value. Tire were flushed and refilled to adjust to the original partial pressure of oxygen value. This compensates for the loss of the cavity gas due to whole tire permeation. The design box encompasses real world conditions. If a tire is filled to 80psi the resulting partial pressure of oxygen is 19.79 psia. The Design of experiment conditions of inputs are maintained using calculated pressures and adjusted based on temperatures to maintain the same level of partial pressure of oxygen levels at all the design points. This novel design of experiment provides us with two studies with a minimal usage of materials and time. The first study is the effect of the 4 inputs on the compounded slabs aging inside the tire reactors. The second study is the effect of time, temperature, and partial pressure of oxygen on the tires used as reactors.

Materials

Compounded Materials 3 types of compounds were formulated based on typical belt coat compounds used in tires. The three compounds are designated by letters A, B and C differentiating the level of antioxidants used 0.5, 1.25 and 2 phr. The formula is shown in Table I. All slabs are compression molded to a uniform thickness of 40 thousands of an inch

FOR USE BY PURGEN98 DEALERS ONLY Page 159 of 168 Tire Reactors 5 tire reactors were used. All 5 tire reactors were of one size and DOT code, a Hankook LT245/75R16 load range E, rated load of 3042 lbs at 80psi Cold with 2 steel, 2 polyester and 2 nylon plies in the tread. Two types of materials were evaluated. A design of experiment was setup to illustrate the effect of the 4 inputs on two types of materials. The design of experiments setup resulted in two superimposed studies. The first is the effect of time, temperature, partial pressure of oxygen, and antioxidant level on compounded material properties aged in tire reactors. The second is the effect of time, temperature, and partial pressure of oxygen on the tire manufactured with an unchanged chemical formulation. For the first study, compounded rubber slabs are aged in specially marked polyethylene bags inside the tire reactors. Tensile specimens are punched out and 3 samples are aged for each design of experiment condition. Additionally intact rubber slabs are aged to avoid severe diffusion limited oxidation conditions.

Fill Gas Nitrogen and oxygen fill gas tanks are obtained from Praxair. The gasses obtained are dry and contain less than 10ppm of moisture. The gas is mixed to achieve the required percent oxygen in the tire reactors based on the design of experiments.

Physical Properties

Oxygen Content Oxygen content of the tire reactors was measured using a Balston ® 72- 730 Oxygen Analyzer from Parker Hannifin Corporation. The Balston 72- 730 Oxygen Analyzer is designed to monitor the oxygen concentration in a process stream, display this concentration in digital form. The Balston oxygen analyzer has been certified to IEC 1010 Standards (CSA 22.2 No.1010.1-92) and bears the CSA safety marking on the product label. The sensing device designed into the Balston 72-730 and 72-O2730NA Oxygen Analyzers is a galvanic cell. The Oxygen Analyzer has an internal temperature compensation circuit to provide accurate readings within a specified temperature range, with an accuracy of ±1% of the calibration gas concentration. The oxygen concentration LED display shows oxygen concentration, in percent, to the nearest 0.1%. The calibration controls are located to the left of the oxygen concentration display. The zero potentiometer is used to zero the instrument when a zero gas (containing no oxygen) is introduced.

FOR USE BY PURGEN98 DEALERS ONLY Page 160 of 168 Tire Pressure Tire pressure measurement is done using as digital pressure gauge with a range of 0-100 psig with pressure resolution of 0.5 psig. The tire pressure gauge is calibrated traceable to a NIST calibration certificate.

Temperature Humidity Measurements Oven aging is calibrated with a NIST traceable Humidity Temperature Meter from Omega with add-on K type Thermocouple.

Tensile Testing Dumbbell specimens were die cut using an ASTM D 638 Type V dumbbell die and tested per ASTM D 412. Samples were tested at 2.0 inches per minute (50.08 cm/minute). Testing was done in a controlled environmental space maintained at 50% relative humidity and at 70 degrees F. Test output includes elongation to break, stress at break, modulus at 25%, 50%, 100%, 200%, 300% and 400% elongation.

Results and Discussions

As stated in the introduction natural rubber belt coat compound ages in the presence of oxygen. Higher the purity of the nitrogen the lesser is the oxidative effect on the belt coat compound.

Fig.1 shows the correlations using a 2x2x2x2x full factorial model with one center point to construct a formulation between time, temperature, antioxidant level, and partial pressure of oxygen. All four input effects are significant in the elongation to break model. The data and correlations indicate that the partial pressure of oxygen is a significant factor in the degradation of the rubber.

Fig 2 indicates the use of a prediction profiler used to maximize the output variable, in this case elongation to break. The JMP program indicates that the significant controlling inputs are temperature, time, and partial pressure of oxygen followed by antioxidant level. It is important to note this conclusion for compound and tire designers. Tire design can significantly affect running temperatures. A lower belt temperature can cause less degradation of the rubber compared to a better compounded belt coat compound in the limits of our study variables. Inclusion of modulus at 100% elongation in the model illustrates that the DLO conditions have affected the model input of modulus.

Fig 3 indicates the Ahagon chart analysis method for the tensile test data. This chart shows the plot of the log of the elongation ratio at break on the y axis and log of the modulus at 100% strain for tensile dumbbells punched out and aged in tire reactors according to the design of experiments. The design of experiments was constructed to illustrate the effect the four input variable on the rubber properties. We observe a negative 6 slope for the compounds aged at high

FOR USE BY PURGEN98 DEALERS ONLY Page 161 of 168 temperature and high partial pressure of oxygen irrespective of the quality of the compound. It is important to note that literature reveals a -0.75 slope for samples aged at a much lower window of partial pressure of oxygen designated by Type I oxidative reactions. However, in our study we aged tensile dumbbells. This affects the data points at high temperature and high partial pressure. A condition of high modulus at the surface due to diffusion limited oxidation exists. Preliminary testing on the Modulus Profiler indicates a worst case condition with a factor of 3 modulus increase between the surface and the inner regions on the slab for the compound with lowest antioxidant aged for the longest time at the highest temperature. This would cause the data point to slide to the right of the chart falling on the -0.75 slope Type I oxidative curve. It is important to note that the lower purity nitrogen data points would lie further down this degradation slope. As the surface modulus controls the elongation to break, our model is not affected. It is important to note that we need to understand better the changes in compounded slab studies as we see this effect in slabs that are only 40 thousands of an inch in thickness.

Fig 4 shows the same chart with data showing tensile dumbbells punched out after the slabs of rubber were aged. This data is different because of the effects of diffusion limited oxidation are different. The slabs aging behaves differently because it acts as a non continuous sandwich of high modulus surfaces with oxygen starved central region. We observe the antioxidant effect as well. The antioxidant migrates to the surface and creates an artificial diffusion limited conditions. The low antioxidant samples shift to the left on the slabs compared to the dumbbells on the Ahagon chart because the samples have a higher diffusion limited oxidation effect.

Conclusions The overall conclusion of this study is as follows • Cavity gas partial pressure of oxygen is a significant factor influencing the rate of degradation of belt coat compound. • Higher temperatures and higher partial pressure of oxygen induce severe property degradation rates on belt coat compounds. • Purity of the nitrogen plays a very significant role in the aging of rubber compounds. • A tire filled with nitrogen will degrade but at a significantly slower rate than tires filled with air. • Further study of the diffusion limited effects in tires and the influence of nitrogen purity on failure pathways, belt edge crack growth in tires and tire durability will be evaluated in a follow up paper.

FOR USE BY PURGEN98 DEALERS ONLY Page 162 of 168 References

1. Aging of Tire Parts during service. I Types of aging in heavy-duty tire Asahiro Ahagon, M. Kida, and H. Kaidou, Presented at a meeting of the Rubber Division, ACS, May 1990 2. Aging of Tire Parts during service. II Aging of Belt-skim rubbers in passenger tires. Hiroyuki Kaidou and A. Ahagon, Presented at a meeting of the Rubber Division, ACS, May 1990 3. J. Baldwin, Effects of Nitrogen Inflation on Tire Aging and performance, ACS Rubber Division, 2004 4. K.T.Gillen, R.L.Clough, and J.Wise, Prediction of Elastomer Lifetimes from Accelerated Thermal Aging Experiments, ACS, 1996, pp557-575. 5. G.J. van Amerongen, Rubber CHEM TECHNOLO. 1065 (1964) 6. Long Term Durability of Tires, N. Tokita, W.D. Sigworth, G.H.Nybakken, G.B.Cuyang, Uniroyal Inc Research Center, International Rubber Conference, Kyoto, Japan, Oct 1985 7. Evaluation of chain scission during mixing of filled compounds, Asahiro Ahagon 8. Oxidative aging of back filled elastomers A. Ahagon, Hiratsuka, Presented at a meeting of the Rubber Division, ACS, Oct 1984 9. Property changes in automotive tyre components in road service, A. Ahagon, International Polymer Science and Technology, Vol. 27, No 3.,2000 10. Oxidative aging of reinforced elastomers L. Nasdala Universitat Hannover, Germany 11. FEA of diffusion –reaction in tires, Norman Welson, Stevens institute of tech, Rubber world Publication Oct 1993 12. The chain end distributions and crosslink characteristics in black filled rubbers, Asahiro Ahagon 13. D.M. Coddington, Rubber CHEM TECHNOLO.52 ,905 (1979)

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TABLE I: Formulation of compound used in the study

Supplier Ingredient Description phr Code Non-productive mix Natural Rubber 100 Carbon Black N326 65 Aromatic Oil 3 ZnO 5 Stearic Acid 2 Manobond Cobalt Naphthenate 0.5 680C TMQ 1

Productive mix ZnO 3 formula A = .5 6PPD formula B = 1.25 formula C= 2 Santogard PVI 0.1 Insoluble sulfur crystex sulfur 80% sulfur 5.6 DCBS 0.7

formula A = 185.50 Total formula B = 186.25 formula C= 187.00

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FIGURE 1: Statistical Design of experiments and Model Fit

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FIGURE 2: Prediction profiler and Desirability Function

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FIGURE 3: Ahagon Chart for belt coat compound tensile dumbbells

AHAGON CHART - TENSILE SAMPLES AGED IN TIRE REACTORS

C1-50-50 average A3-50-5-average C3-50-50 average A1-50-50 average 0.88

A3-50-50 average

0.78 A4-70-5-average A1-50-5-average LOW TEMP LOW O2

C3-50-5-average 0.68 C1-50-5-average C4-70-50 average LOW TEMP HIGH O2

0.58 C2-70-5-average A4-70-50 average LOG Lambda LOG

C4-70-5-average HIGH TEMP LOW O2 B5-60-27.5 (19.67) average 0.48 A2-70-5-1-average

B5-60-27.5 (28) average

0.38 A2-70-50 average

DATA POINTS HIGH TEMP HIGH O2 AFFECTED BY SEVERE DLO CONDITIONS 0.28 0.58 0.63 0.68 0.73 0.78 0.83 0.88 LOG M100

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FIGURE 4: Ahagon Chart for belt coat compound slabs.

AHAGON CHART - TENSILE SLABS AGED IN TIRE REACTORS

0.88

0.78

0.68

0.58 LOG Lambda

0.48

0.38

0.28 0.58 0.63 0.68 0.73 0.78 0.83 0.88 LOG M100

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