GF-6, PC-11 and Dexos1™: New Engine Oil Speciﬁcations Mean New Additive Challenges

TECH BEAT Dr. Neil Canter / Contributing Editor SPECIAL REPORT GF-6, PC-11 and dexos1™: New engine oil speciﬁcations mean new additive challenges

Additive suppliers will need to develop new additives and KKEKEYY COCONCEPTSNC TS formulation approaches to • ThThee iimplementationp of ttwowo subcategoriessubcategories in thethe uppcocomcomiing GFGF-66 sppececificaecificationificatioonn forfor PCPCMOsCMOs meet specification deadlines. meanmeanss tthathat additivadditivee formulations maymay neeneedd ttoo be ddesidesignedggned differentldifferentlyy for GF-6GF-6 A anaandd GFGF-6- 6B.B • FFoor tthe new HDEOO sspecificaspecification,pecificationon, PCPC-1C-11,, the newnew llowero e viscosityviscosity oiloil subcategory,ssubcategory, PC-1PC-11B THE LUBRICANTS INDUSTRY IS IN THE MIDST OF DEVELOPING PROD- representts a significantsignificant challengechallenge because of UCTS for not one but three new engine oil specifications at the thethe poppotentialotteennttial neneedeed tot inincorincorporatecorpporaatte newneneeww frictionfrfricictition same time. Further complicating the issue—two of the speci- moddifieerss witth more eeffeecttive aanttiweear addddittivees.. fications are further organized into specific subcategories. • ImImplementationplementation of tthehe secosecondnd ggenerationeneration With passenger car motor oils (PCMOs), the new specification is known as GF-6.1 It is further segmented into two GM specificaecificationtion, ddexos1™exos1™ priioor to GGF-6F-6 mamayy subcategories: GF-6A and GF-6B. GF-6A will cover existing requirei e thethe lullubricantsububricantbric ca tss iniindustryndustrdu tryy to reformulaterereformulatrmul te engine oil grades while GF-6B will cover new grades with PPCMOsCMOs again. viscosities lower than 0W-20. The impetus for the new grade comes from the request by automotive manufacturers to rec-

10 The heart is typically the size of a fist: 12 cm (5 inches) in length, 8 cm (3.5 inches) wide and 6 cm (2.5 inches) new lower viscosity engine oils with an HTHS of 2.9-3.2. At the time of this article’s publica- GF-6 LUBRICANTS tion, the first license date for PC-11 will be in December 2016. GF-6 will PROVIDE SOLUTIONS probably move to a March 2018 first license date. TO GROWING The third engine oil specification is the second generation GM specification REGULATIONS FUEL ECONOMY .5 known as dexos1™ that is due to be 54 mpg DEMANDS. implemented in September 2016.

There have been steady fuel economy Efficiency performance mandates increases since 2009. continue to affect the automotive in- New fuel economy requirements will skyrocket to 54.5 mpg by 2025. dustry. In the U.S. sweeping legislative .0 changes put into effect by the National LUBRICANT EFFICIENCY 18 mpg Highway Traffic Safety Administration † GF-6 LUBRICANT EFFICIENCY (NHTSA) in 2012 require a fleet-wide GF-5 average of 54.5 mpg (U.S.) by 2025 GF-1 (see Figure 1). Fuel economy performance is being raised not just in terms * * * * of the level of fuel economy but also in 13% 15% 51% 42% terms of durability over a longer time .5 .5 .3 .6 .3 .5 18-20.4 20 -23 24 -36 38 -54 mpg mpg mpg mpg period. Efficiency is at the forefront of

†Lubricant efficiency determined by ILSAC (International Lubricant Standard Approval Committee) Sequence VI Fuel Economy Testing. *These numbers reflect the NHTSA’s regulated fuel economy increases through 2025. FUEL ECONOMY CONTRIBUTIONS SPECIFICATIONS WE ALL NEED TO DO LUBRICANTS MUST CONTRIBUTE TO DURABLE FUEL ECONOMY OUR PART. OVER LONGER MILES.

OEM Lubricants with GF-5 novel additive % FEI SUM †† ** 1.9 5W30 6.5K Lubricant chemistrymistrym andannddl lloweroower Industry viscosities will MILES enable new engine technologies and GF-6 Figure 2 | The lubricants industry is facing % FEI SUM †† directly contribute to 2.9 ** Engine MFG 5W30 10K a major challenge in developing products fuel economy. MILES

†† for three speciﬁcations where efﬁciency FEI SUM =Combination of initial and aged fuel economy improvements of Sequence VI test. **Simulated drain interval in the Sequence VI fuel economy test. improvements are required. (Figure courtesy of The Lubrizol Corp.)

GF-6, PC-11 and GM specifications— Figure 1 | Improved fuel efficiency is a key requirement that PCMOs will need to meet in the three current specification upgrades upcoming GF-6 specification. (Figure courtesy of The Lubrizol Corp.) greatly impacting the industry (see Figure 2). The development of these new engine oil specifications means that there ommend lower viscosity grades for engine oils (HDEOs). Further segmen- are certainly additive challenges that their vehicles. GF-6B covers engine tation of this engine oil category is the lubricants industry must meet. In- oil viscosities lower than 0W-20. Re- made based on backward compatibility. put on how the industry is responding cently the Japanese automaker Honda Two subcategories are based on a dif- has been obtained from the following requested two lower viscosity grades ference in high-temperature high-shear companies: (0W-12 and 0W-8) be added to the (HTHS) viscosity rates. The subcate- • Afton Chemical Corp. Engine Oil Viscosity Grade Classifica- gory, PC-11A, will be compatible with • Chemtura Corp. tion System. the current HDEO category (API CJ-4) • Chevron Oronite Co. The second engine oil specification, and have an HTHS of 3.5 minimum; • Croda known as PC-111, 2, is for heavy-duty the second subcategory, PC-11B, is for • The Dow Chemical Co.

in thickness. A man’s heart weighs about .28 kg (10 ounces), a woman’s about .22 kg (8 ounces). 11 • Evonik Oil Additives USA pre-ignition and wear protection for Co. in Midland, Mich., offers this analy- • Infineum USA LP various engine components.” sis of the upgrade for the Sequence IVB • The Lubrizol Corp. Tung makes two additional impor- valve train test: “The new test includes a • Vanderbilt Chemicals LLC. tant points about the reason for devel- more severe duty cycle, which is a high- oping GF-6. He says: “Each of the new ly transient cycle compared to the origi- GF-6 UPGRADES tests addresses requests by OEMs based nal test. In addition, the test duration The proposed ILSAC GF-6 specifica- upon the needs of modern, high-tech increases from 100 hours to 200 hours, tion will enable a new level of perfor- engines. With these new technologies which makes the test more severe from mance for passenger car engine oils in come new requirements of the lubri- a valve train wear perspective.” the era of efficiency. Martin Birze, The cants that enable them. The new tests Steve Haffner, North America Lubrizol Corp.’s regional business man- also address the increasingly limited crankcase market manager for Infine- ager, passenger car additives in Wick- availability of older engine parts. Sim- um USA L.P. in Linden, N.J., gives his liffe, Ohio, says, “the proposed GF-6 ply put, engines used to run tests under perspective on GF-6. He says, “The specification is a significant upgrade GF-5 are reaching the end of their use- new PCMO specification is being de- that addresses the demands of new ful life, and parts are limited or unavail- veloped to protect the newer hardware engine technology. This technology able, necessitating replacement tests to being introduced into the field includ- requires higher-performing engine oils meet new engine requirements.” ing smaller displacement, direct-inject- to enable efficiency while also deliver- Tiffany Murphy, marketing manager ed gasoline engines. These new oils will ing the higher fuel economies required for PCMO for Afton Chemical in Rich- be expected to deliver enhanced oil ro- by mandated regulations. mond, Va., says, “The GF-6 category bustness and wear protection as well as “GF-6 is unprecedented in its pro- will again seek to define an engine oil increased fuel economy throughout the posed inclusion of six new engine tests. with improved durability characteris- oil change interval.” Four are replacement tests being updat- tics and better fuel economy perfor- ed with new hardware, and two are en- mance to help equipment manufactur- ADDITIVE CHALLENGES FOR GF-6A tirely new tests. The specification will ers meet the future EPA CAFE targets.” AND GF-6B push the industry’s approach to engine STLE-member Dr. Frank DeBlase, At this time there is some disagreement oil formulation to greater heights.” Chemtura Fellow-petroleum additives among the respondents about the sta- STLE-member Kaustav Sinha, glob- in Middlebury, Conn., has focused his tus of the two GF-6 subcategories and al project manager for Chevron Oronite research on novel antiwear agent, an- even if there will be two sets of specifi- Co. LLC in Bellaire, Texas, overseeing tioxidant and friction modifiers. Says cations or one. the GF-6 development, provides an DeBlase on the new subcategory GF- Murphy says: “The new GF-6B cat- overview of the six new engine tests 6B: “The new lower viscosity GF-6B egory defines the performance require- being developed for GF-6. oil (0W-16 or 5W-16), with a lower ments for ultra-low viscosity grades be- Says Sinha: “The Sequence IIIH oxi- high-temperature high-shear (HTHS) low SAE XW-20 and as such is distinct dation/deposit and Sequence IVB valve viscosity, should deliver improved fuel from GF-6A with no overlap at all. The train wear tests will get engines and economy and lower green-house gas viscosity grades appropriate to GF-6B test procedures developed by two new emissions but will require additional will only be recommended by selected Original Equipment Manufacturers engine protection. Therefore, new tests OEMs for specific engines and vehicles. (OEMs), Chrysler and Toyota, respec- are being developed to assess increased “So the challenge, in a sense, is tively. Ford is refreshing the Sequence fuel economy performance and engine greatest for the oil marketer to ensure V sludge performance test and also durability. These requirements will be that such oils are clearly identified by developing two brand new tests (low addressed by new lubricant and addi- consumers and are only used in the speed pre-ignition (LSPI) and chain tive technologies.” appropriate applications. From a de- wear) for the category. GM is refreshing Scott Davis, key account manager– velopment perspective, it is important the Sequence VI fuel economy test.” lubricants for Croda in New Castle, to ensure that the performance limits STLE Fellow Dr. Simon Tung, global Del., stresses the challenge of meet- defined for GF-6B oils are appropriate OEM liaison manager for Vanderbilt ing more rigorous fuel economy re- to this category and are not simply an Chemicals LLC in Norwalk, Conn., quirements. He says, “A key objective extension of GF-6A.” says, “In moving beyond GF-5 require- of GF-6 is to improve fuel economy Haffner raises the point that the ments, GF-6 will incorporate increased versus GF-5. The Sequence VIE fuel industry is unsure if there will be one fuel economy through the oil change economy test replaces the VID with the specification or two subcategories. He interval, enhanced oil robustness for proposed limits for the newer test being says, “The two subcategories may be spark-ignited internal combustion en- on average about 50% higher.” required to reduce end-user misap- gines, formulations to help minimize STLE-member Ashish Kotnis, senior plication. The GF-6B specification is the occurrence of low-speed engine research scientist for The Dow Chemical currently designed for oils operating

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© 2014 Quaker Chemical Corporation. All Rights Reserved at viscosity ranges less than the Xw-20 and these oils will not be back service- able, so misapplication is a concern for some OEMs.” DeBlase believes that changes in the treat rate of certain additives and use of more durable base oils are needed for GF-6 in general and specifically GF-6B. He states, “The lower viscosity GF-6B oils will likely require more effective friction modifiers and antiwear additives. Maintaining boundary lubrication and wear protection by using more sulfur- and phosphorus- containing metal antiwear and friction modifiers might compromise pollution control devices or generate higher deposits. The preferred choice to mitigate Figure 3 | Incorporation of a Group V co-base stock in different base oils leads to an increase this problem is additional organic fric- in VI independent of the base oil used. (Figure courtesy of The Dow Chemical Co.) tion modifiers and antiwear additives for even greater boundary lubrication while maintaining elastohydrodynamic lubrication.” DeBlase continues, “The longer drain intervals required in GF-6 will be assisted by more oxidation-resistant base oils such as gas-to-liquid synthetic oils, polyalphaolefins, polyolesters or polyalkylene glycols. Extended drain intervals also will require the use of more or better antioxidants and additives capable of providing sustained boundary lubrication over high mileage intervals.” Kotnis explains that the challenge in moving to GF-6B is that oils are thinner at higher temperatures, which impacts the film thickness and can result in a faster transition from the elastohydrodynamic lubrication to a mixed lubrication regime. He says, “Special additive Figure 4 | Friction reduction is observed in traction coefficient testing when a Group V co- technologies are being developed to base stock is added to a commercial 5W-20 engine oil. (Figure courtesy of The Dow Chemical Co.) protect the engines that will use these lower viscosity grade oils. For example, data shown in Figures 3 and 4 show how a Group V co-base stock incorpo- will be deciding the contribution the oil can be selected to achieve the desired rated into currently used base oils can marketer can realize from an improve- fuel economy performance level.” increase the viscosity index (VI) of the ment in fuel economy. Careful selection The proposed ILSAC GF-6 upgrade base oils and reduce the friction seen in of the VI improver, such as the use of a encompasses two specifications: GF-6A a commercial 5W-20 engine oil.” comb polymer, can reduce viscosity at and GF-6B. The principle difference be- Phil Hutchison, Asia Pacific regional intermediate oil temperatures and di- tween the categories concerns viscosity technical manager for Evonik Oil Addi- rectly influence fuel economy. The VI grade and HTHS performance. GF-6A tives in Singapore, offers this analysis improver type should be considered as and GF-6B provide the same level of on the role of VI improvers: “The real a formulation tool alongside other ad- durability performance, but for GF-6B choice affecting VI improver selection ditives such as friction modifiers and the aim is lower HTHS to deliver fur-

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SURFACE COMPRESSION FLUID PROTECTION RESISTANCE PROTECTION FRICTION

LUBRICANT PARAMETERS

TECHNICAL PARAMETERS BOUNDARY MIXED EHD/HD (ENVIRONMENT-CONDITIONS) ADDITIVE FEATURE Surface Protection Compression Resistance Fluid Protection ADDITIVE BENEFIT Wear Reduction Surface Separation protects surfaces regardless of friction maintains fluid strength and Fluid Integrity ( ) protects against fluid degradation DESCRIPTORS/DEFINITION need for optimal friction management delivers surface repulsion Extreme Pressure Agents Anti-oxidation Agents SOLUTIONS Film Strengtheners Surface Activated Additive Systems Friction Modifiers Contamination Control Agents Anti-wear Agents Viscosity Management Agents

Figure 5 | The trend toward lighter and smaller engines means that new additives must be developed for use in lubricants that will need to operate in the boundary layer. (Figure courtesy of The Lubrizol Corp.)

ther fuel economy benefits. lenges us to change our perspectives cation of specific additive components Ray Calder, Lubrizol’s global busi- on how we look at the role of additive or a different formulation shape may ness manager, passenger car additives chemistry in lubricant formulations. be required to deliver the antiwear and in the U.K., looks at the different lu- Our approach is an innovative technol- durability requirements needed in GF- bricant regimes in play in an engine as ogy called Surface Activated Additive 6B engine oils.” shown in Figure 5. He says, “Advances Systems (SAAS).” Davis comments on GF-6A and in engine hardware technology along Tung expresses concerns that exces- GF-6B: “There is substantial overlap with lower viscosity are increasing the sive engine wear and durability could between GF-6A and GF-6B. Essen- need to protect the engine—particu- be found in using low viscosity, GF-6B tially the only difference between the larly where metal parts touch during engine oils. He says, “Lower viscos- two subcategories is the GF-6B HTHS boundary operation. During boundary ity grade oil might not be able to have viscosity is lower.” operation, additives become critical to enough oil film thickness to protect Sinha believes that finding the right protecting parts and enhancing per- engine wear as higher viscosity grade additive balance is needed for success- formance. The performance of the lu- oils. The improvement in fuel economy fully developing engine oils for GF-6A bricant in this regime is outside of the performance seen with lower viscos- and GF-6B. He says, “Mitigation of influence of viscosity effects, relying on ity engine oils also may have a nega- low-speed pre-ignition (LSPI) com- additives to keep parts protected and tive impact on durability because the bined with delivering fuel economy, en- vehicles efficient. Creating this perfor- oil film is less robust under the most gine cleanliness and wear performance mance differentiation in the boundary extreme loading and high-temperature in a cost effective manner will be key to regime through additives brings about conditions encountered with emerging developing additives and products for a new era of additives science that chal- engine technologies. Enhanced fortifi- GF-6A and GF-6B. While GF-6B is pri-

WWW.STLE.ORG TRIBOLOGY & LUBRICATION TECHNOLOGY SEPTEMBER 2015 • 15

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Ben Woeste NORTHEAST REGION ACCOUNT MANAGER base stocks compared to GF-6A oils. to new engine tech- Since the films formed with the lower nology. Contaminants viscosity base oils will be thinner, some from combustion en- advances in the antiwear additives like ter the lubricant sump zinc dialkyldithiophosphates (ZDDPs) as a result of blow-by and boron-containing additives might and accumulate in be required for engine wear protection. the lubricant leading Also, since these oils need to have the to increased timing same weighted piston deposits and chain wear. The test viscosity increase in the Sequence IIIH will effectively mea- test, they might require improved de- sure a lubricant’s abil- tergent technology.” ity to minimize timing In formulating for GF-6A and GF- chain wear as it relates 6B, Birze contends that managing to induced wear by boundary lubrication is an essential the soot-like particles area of focus for additive innovation. produced by GDI en- Figure 6 | The frequency of LSPI occurring is dependent upon the He says, “Lighter viscosity lubricants, gines.” engine oil formulation. (Figure courtesy of Chevron Oronite Co. LLC.) advanced hardware and changing op- One of the pro- erating conditions cause a shift toward posed tests for the boundary lubrication. Lubricants in GF-6 specification each subcategory will need to pass all evaluates an oil’s ability to prevent ignition to occur. A second hypothesis the same GF-6 tests. However, with LSPI, a critical challenge as GDI en- is that lower molecular weight and thus GF-6B, lower viscosities will require gines become common. Automakers more volatile components in the engine unique formulations in order to main- have mitigated LSPI by introducing ad- oil can mix with fuel in GDI engines, tain durability and robustness. The se- ditional fuel to the engine at the points which can form an ignitable mixture at lection and balance of additive chem- where LSPI is likely to occur. The fuel low temperatures that can produce the istry and other components is critical. helps cool the cylinder, reducing the knock. To minimize the knock, more SAAS technology delivers a thick film likelihood of LSPI. However, Birze is purified oil with lower NOACK volatil- of protection—a complex layer of ad- concerned that this approach can re- ity oil might be needed.” ditive technology tailored to the appli- duce performance. He says, “While Kotnis continues, “GDI engines cation.” effective, this method is necessarily tend to produce more soot, which can counterproductive, as the additional impact timing chain wear. There might LSPI AND TIMING CHAIN fuel prevents the engine from achieving be advancements in dispersant technol- WEAR TEST peak fuel economy. Lubricant formula- ogy required to keep this soot dispersed Tung provides background on both tions can be part of a solution that may to reduce timing chain wear.” new tests for GF-6. He says, “The LSPI alleviate the need for using additional With regard to LSPI, Sinha believes test was developed to address issues fuel.” that the right additive balance must around gasoline direct injection (GDI) Murphy says, “It is too early to be developed. He says, “As noted in technology that OEMs are utilizing to provide a definitive answer about how Figure 6, the frequency of LSPI can reach fuel economy goals. LSPI can these two tests will impact the selec- vary depending upon the engine oil occur at low engine speed and high tion of additives for GF-6. But these formulation. Based on years of R&D loads that are prevalent in GDI and new tests shift the emphasis of formu- work in this area, we understand the turbocharged gasoline direct injection lation in a different direction to other formulation levers required to show (TGDI) engines. LSPI is a new issue tests within the GF-6 category, so it will discrimination between low and high due to modern powertrain systems clearly be a challenge for oil formula- LSPI events. Engine wear upon oil and can be difficult to predict. The test tors to ensure that the holistic perfor- degradation is one phenomenon that also assumes greater importance be- mance of future technology platforms has been observed across both the Se- cause most OEMS recently indicated with enhanced durability and fuel quence IVB valve train and chain wear that their next generation engine oil economy properties will be achieved.” tests. Based on our work, it could either requirements will include an LSPI fre- Kotnis speculates about how for- be a combination of all or part of the quency assessment as well as specifi- mulations might need to be adjusted additive system (dispersant/detergent/ cations around turbocharger deposit to meet the LSPI and timing chain wear antioxidant/antiwear), depending on control.” tests. He says, “One hypothesis for pre- the outcome of the ongoing test devel- Tung continues, “The timing chain ignition is that some of the particles in opment activities.” wear test is being developed in response dirty oil, like soot, can cause the pre- Haffner feels that the two tests can

18 The average adult heart beats 72 times a minute, 100,000 times a day, 3.6 million times a year and 2.5 billion times during a lifetime. potentially have a large impact on additive selection. He says, “LSPI is stochas- tic (as GM has termed it), occurring at very low engine speeds and prior to ignition, while timing chain wear tests look at lubricant contamination and the effect this can have on timing chain wear.”

PC-11 UPGRADES Kyle Fricke, senior marketing specialist for HDEO for Afton Chemical in Rich- mond, Va., discusses the move by the lubricants industry from CJ-4 to PC- 11. He says, “The PC-11 category represents a clear performance improvement compared to CJ-4. The OEMs want oils with improved robustness characteristics to cope with increased thermal stress placed on them with the Figure 7 | The current North American PC-11 product tiers are shown. (Figure courtesy of Afton latest emissions compliant engine de- Chemical.) sign platforms.” Fricke continues, “Use of CJ-4 oils is anticipated to decline as the industry moves to the new higher-quality products, although a number of market and economic factors can influence the speed of that transition. With the introduction of PC-11, the market is expected to transition to alternative viscosity grades (i.e., away from traditional 15W-40) at a greater pace than simply through the use of new grades in new trucks. This means a significant increase in use of 10W-30, 5W- xx and 0W-xx oils. However, this will not simply be a change at the PC-11A or CK-4 performance level as different customer segments will be attracted by the potential operational cost savings associated with the move to low viscosity, fuel efficient PC-11B oils and some OEMs or operating companies may Figure 8 | A larger number of viscosity grades will probably be offered in the post North promote the use of low phosphorus or American PC-11 market. (Figure courtesy of Afton Chemical.) universal oils.” Figures 7 and 8 show the transition from the current HDEO product tiers to the larger number of viscosity grades new category is scheduled for first li- diesel engine additives in Wickliffe, that will probably be offered in the post censing on Dec. 1, 2016. PC-11 was Ohio, “The continuing drive for fuel PC-11 market. designed to meet industry needs for economy improvements is likely to Proposed Category 11 (or PC-11) higher performance, greater fuel effi- command more fuel efficient engine is the next heavy-duty engine oils per- cient heavy-duty engine oil technolo- oils enabled with lighter HTHS viscos- formance category, superseding the gies while enhancing engine durability. ity without compromising durability. existing API CJ-4, in development by According to Keith Corkwell, Lubrizol’s Today, the U.S. market is dominated the American Petroleum Institute. This global business manager-heavy-duty by SAE 15W-40 lubricants in diesel

WWW.STLE.ORG TRIBOLOGY & LUBRICATION TECHNOLOGY SEPTEMBER 2015 • 19 engines, but it is likely that, with the resolution is to increase the treat rate viscosity specification (more demand- advent of PC-11, we will see increased of metal, phosphorus and sulfur con- ing for PC-11B), which can rapidly use of SAE 10W-30 and 5W-30 oils.” taining additives to respond to the po- increase at the end of the antioxidant PC-11 has been driven by the U.S. tential wear, but phosphorus and metal performance life.” Government, which is emphasizing the limits need to be taken into account.” Gerald Shaw, America’s region au- need for improved fuel economy and tomotive engine oil product line man- reduced carbon dioxide emissions. ADDITIVE CHALLENGES FOR PC-11A ager for Chevron Oronite in Bellaire, Haffner adds, “PC-11 oils also will of- AND PC-11B Texas, believes that a key challenge is fer improved protection from higher Haffner contrasts PC-11A as offering maintaining wear performance between engine temperatures, improved shear increased engine protection at tradi- the two subcategories since PC-11B is stability and a reduction in engine oil tional viscosities such as SAE 15W-40 a lower viscosity oil with lower oil film aeration.” while PC-11B is the so-called “fuel thickness. Shaw says, “The two subcat- Tung says, “The primary driver for economy grade” designed to meet the egories overlap significantly in what is PC-11 came from a regulation issued evolving market needs for fuel econo- needed in formulating for the oil’s per- by the NHTSA in 2011 limiting green- my. He says, “PC-11A is recommended formance. The biggest challenge is the house gas emissions and requiring fuel by on- and off-road OEMs and will be application of advanced antiwear sys- economy improvements for medium- fully backward compatible. The dura- tems to help ensure wear performance and heavy-duty trucks during a 2013- bility requirements will be the same for with lower viscosities.” 2018 phase-in period. The EMA then PC-11A and PC-11B to ensure that the Fricke says, “The application range asked API to develop PC-11.” new fuel economy grades are risk-free. of the new PC-11 specification repre- Tung continues, “Besides fuel econ- But, similar to GF-6B, PC-11B oils may sents the biggest change for the market omy improvement and carbon dioxide have little or no back serviceability and and for both equipment operators and emission reductions, other needs for not all OEMs are expected to recom- oil marketers. PC-11 will introduce a PC-11 are driven by increasing bio- mend PC-11B at least at the start.” more restrictive specification for oils diesel use and the need for improved Commenting on PC-11A and PC- that meet the performance require- protection from higher engine tem- 11B, Corkwell notes, “PC-11A is de- ments of both heavy-duty diesel and peratures, improved shear stability, ad- signed as a broad fit for existing trucks, gasoline engines—universal or mixed- hesive wear protection and reduction requiring higher levels of protection fleet oils—with a tighter specification or elimination of engine oil aeration. and performance for end-users than on phosphorus levels for these oils for In summary, PC-11 development is those established by API CJ-4. While exhaust catalyst compatibility. There focused on better fuel economy and lubricants classified under PC-11A are also is greater interest in the develop- green environmental compatibility with broadly backward compatible to exist- ment of the new PC-11 category from emerging powertrain technology and ing commercial vehicles, this category global OEMs who have developed a emission system complexity.” nevertheless represents a major step up closer association with North Ameri- Gary Parsons, global OEM and in- for performance and will require sig- can OEMs through the lifetime of the dustry liaison manager for Chevron nificant investment. PC-11B reflects CJ-4 category.” Oronite in San Ramon, Calif., provides the increasing adoption of low-viscos- Tung summarizes, “PC-11A and details on the new engine tests for PC- ity lubricants in engine hardware and PC-11B must ensure that the low HTHS 11. He says, “The Volvo T-13 is used will standardize these advanced prod- oils still deliver the same level of engine to assess the thermal stability and re- ucts without sacrificing protection and protection as defined in current API sistance to oxidation/nitration. Perfor- durability.” Using more fuel-efficient CJ-4 engine tests and in the upcoming mance in this test is targeted at helping engine oils has the dual benefit of PC-11 engine tests.” ensure engine oils will continue to per- achieving environmental goals while form during extended drain intervals. at the same time reducing the cost of MEETING NEW PC-11 REQUIREMENTS The Caterpillar C13A test measures the operations for the fleet.” DeBlase predicts that proper base oil engine oils ability to resist aeration. DeBlase stresses the need for us- and additive selection will be critical. Aeration of engine oil can lead to a ing antioxidants to meet the require- He states, “PC-11 requirements for fuel degradation of performance in engines ments for both PC-11 subcategories. efficiency will likely be met by a com- equipped with variable valve timing.” He states, “The use of higher treat rates bination of base oil improvements and DeBlase expressed concern that and more effective antioxidants can increased usage of antioxidants, fric- moving to lower viscosity HDEOs may help handle future viscosity decreases tion modifiers and antiwear additives. lead to the need to adjust the additives with PC-11. Longer drain intervals re- However, in diesel engines the develop- used. He states, “Ring scuffing could be quire that higher temperature decom- ment is more challenging, due to the an issue as it is increased upon moving position of antioxidants needs to be hotter operating temperatures expected to lower viscosity HTHS. A short-term minimized in order to maintain the oil and needed to maintain viscosity. The

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www.huntsman.com/metalworking impact of treat rates on air release may need to address higher engine tempera- the older categories and will not exist need to be addressed, and the proper tures and shear stability. According to within the finalized version of PC-11. use of additives such as oil-compatible Corkwell, “One way to make an engine Adhesive wear within an engine is an high molecular weight polymeric sili- more fuel efficient is to make it more either/or scenario. The problem oc- cone antifoams, considered.” thermally efficient, and manufacturers curs or does not occur with no middle Hutchinson says, “Further fuel are increasingly exploring this route. ground. However, through extensive economy improvement within PC-11B When an engine runs at a hotter tem- industry activity, we have been able to should be possible by careful selection perature, so does the oil lubricating it, advance the development of a scuffing of the VI improver type with comb and protection becomes more challeng- test that relates to real-world experi- polymers being optimal. The key for ing due to the drop in viscosity. Oxi- ence. While outside of PC-11, once PC-11B will be a VI improver deliver- dation also is more likely to occur at finalized, it is expected that a scuffing ing a good HTHS 150 C before and af- higher temperatures. For these reasons, test will become part of OEM approval ter shear combined with low oil viscos- PC-11 engine oils will need to be more requirements, due to the associated ity at more intermediate temperatures oxidatively and thermally stable.” benefits this testing brings.” so fuel economy is optimized without Corkwell continues, “PC-11 will re- Addressing the challenges of simul- a compromise in durability.” quire high-shear stability of lubricants, taneously developing additive tech- Shaw states that a fresh additive ap- helping them maintain the same level nologies for three specifications, Birze proach is needed in formulating PC-11 of protection after passing through the concludes, “GF-6, PC-11 and second engine oils to meet the new require- various parts of engines. New require- generation dexos1 technology require ments of the specification. He says, ments will ensure that lubricants still significant resources. Additive suppli- “Fuel economy can be enhanced by offer the same protection under these ers need to cover a wide range of ca- designing lower friction formulations conditions and that the original design pabilities and invest in them. Only by through unique components such as a viscosity does not drop below accept- doing this can we create innovations, novel heavy-duty friction modifier. Im- able levels.” test them and confidently bring them proved oxidation and wear protection One area of concern that PC-11 to market.” can be achieved by carefully balancing does not examine is adhesive wear and Haffner feels that the new PC-11 antioxidation systems and using an in- scuffing—the point at which two pieces requirements will be met by examin- novative valve train antiwear compo- of metal at the microscopic level adhere ing the critical areas of fuel economy in nent.” to each other under intense heat and heavy-duty diesel engines and learning Tung focuses on three new PC-11 subsequently damage each other upon how to maintain engine durability in tests that evaluate aeration control, movement. Corkwell explains, “No a low-viscosity regime. He says, “The wear, corrosion and oxidation and test for this problem, which can cause new additive platforms for PC-11 will scuffing. He says, “The Caterpillar catastrophic engine damage, exists in offer the ability to cover multiple vis- C13 has been developed cosity grades to suit the di- because the test currently verse needs of the market.” used for aeration in API CJ-4 does not adequately LOWERING PC-11 PHOS- address Caterpillar’s aera- PHORUS LIMIT tion concerns. Mack T-13 As explained by Fricke, addresses several criteria universal oils that can op- including ring and liner erate in both gasoline and wear, bearing corrosion, diesel engines will need to oxidation and nitration operate at a lower phos- control as defined by lead phorus limit (800 ppm as levels in the used oil and compared to 1200 ppm) oil consumption. Daimler to meet the GF-6 specifi- DD13 addresses scuffing of cation. He says, “Univer- rings, liners and bearings. sal oils are low total base This DD13 scuffing test, number, low phosphorus still under development by engine oils that are spe- Daimler, has the objective cially engineered to com- of minimizing future con- ply with gasoline after- cerns of scuffing wear by Figure 9 | Use of ashless antiwear components in combination with a treatment systems and not low-viscosity engine oils.” lower phosphorus content can achieve better wear results in the Cum- poison the catalysts. These PC-11 engine oils will mins ISM engine test. (Figure courtesy of Chevron Oronite Co. LLC.) oils will be new to the mar-

22 Did you know? Two-thirds of STLE members are lubricant manufacturers, additive ketplace, replacing the “CJ-4/SN” claim be more pronounced for the lower vis- benefits for both GF-6 and PC-11. He capability. cosity oils needed to meet PC-11B.” says, “VI improvers will play a critical Fricke continues, “In all probability, role in GF-6 in determining the over- the biggest concern will be convincing ROLE OF VI IMPROVERS all rheological profile of the lubricant, consumers that the new oils entering The growing importance of VI im- which in turn controls viscous losses the market will continue to protect provers as additives to not only enable that impact fuel economy. However, their equipment in an identical fash- engine oils to operate efficiently over VI improvers also must be efficient in ion to traditional 15W-40 engine oils. a wide temperature range but also to thickening in order to minimize poly- For example, owners/operators may be assist with friction reduction raises mer contributions to piston deposits wary of lower phosphorus engine oils the question about the role of this ad- for both passenger car and heavy-duty because many of them have been con- ditive type in both GF-6 and PC-11.3 oils. For PC-11, heavy-duty engines ditioned to think that ZDDP is one of Hutchinson says, “Viscosity control operate in a severe environment that the most critical additives in a finished at different temperatures will be the can lead to mechanical breakdown of fluid. Market acceptance will undoubt- key in using VI improvers as a signifi- the polymer chain. Certain VI improver edly be slow at first.” cant tool to achieve high levels of fuel polymer architectures provide higher Phosphorus reduction means that economy in both engine oil specifica- stability for extended shear, which can the best method to evaluate the effi- tions. High HTHS 150 C viscosity, both be a benefit for extended drain intervals cacy of universal oils is through wear before and after shearing, required for in heavy-duty applications.” testing. The Cummins ISM engine test durability and also to meet the engine that measures engine wear and deposits oil standards, will be required along- DEVELOPING ADDITIVES FOR GF-6 under heavy-duty operating conditions side lower oil viscosity at intermediate AND PC-11 is the desired technique to use. Shaw temperatures (40 C, 80 C and 100 C) to Most respondents to the question of the presents data from that test (see Figure deliver fuel economy. The proven abili- difficulty in developing additive tech- 9 on page 22) showing the results of an ties of comb polymers will make them nologies for GF-6 and PC-11 simulta- advanced approach. He says, “Use of ideal choices in GF-6 and PC-11.” neously cited the large commitment in ashless antiwear components in a bal- Haffner says, “The main notewor- R&D resources and time needed. The anced formulation affords better results thy comment is that the amount of VI industry contacts indicate that many than what are seen with conventional improvers required in low-viscosity of the chemistries are common to both formulations. All other performance engine oils such as SAE XW-16 will be specifications but the formulations are attributes also are met with this new reduced. But note that any contribution different because the environments in formulation.” from VI improvers to reconcile lower gasoline engines and heavy-duty diesel Haffner makes the case that formu- viscosity with engine durability will be engines are quite different. lation costs will increase in trying to of greater importance.” STLE-member Mark Sztenderow- develop a universal oil. He says, “In Ian Atherton, senior marketing icz, global manager, automotive engine general, it is more costly to formulate manager for engine oils for Afton oils product development for Chevron at a lower phosphorus level. ZDDPs are Chemical in Richmond, Va., indicates Oronite in Richmond, Calif., details one of the most cost effective antiwear/ that VI improver use will be associated the significant challenge faced by the antioxidant additives available and low with shear stability. He says, “The PC- lubricants industry in working on two ZDDP formulations need to be supple- 11 specification requirements are still major engine oil specifications at the mented with alternative additives. One being finalized, but it is anticipated same time. He says, “Historically there of the real issues with low phosphorus that the new specification will result have been substantial gaps in time be- HDEO formulations is the level of com- in more utilization of 25 SSI VI im- tween heavy-duty diesel and passenger fort of OEMs and end-users due to the provers compared to more traditional car performance updates leading to lesser amount of field experience that 35 SSI polymers. Some oil marketers new API categories. This has helped to exists, in particular in older engines.” would likely still be interested in main- spread out the effort and allow resourc- DeBlase foresees the need to use taining heavy-duty grades on a 35 SSI es to be focused on one or the other. fortifying organic additives to assist VI improver if the specification enables In this case, however, resources needed in boosting the performance of low- them to make a 15W-40 grade with this to develop new heavy-duty and passen- phosphorus-containing HDEOs. He polymer. However, it is clear that, par- ger car lubricants are stacked together, states, “With the higher operating tem- ticularly for grades outside of 15W-40, leading to severe demands in every peratures associated with diesel engines the market will likely have to use a 25 area. Engine and bench test laborato- and the potential for oil thinning, es- SSI option.” ries are being pushed to new extremes pecially if shearing of the VI improver Alex Boffa, global VI improver tech- with all of the new test demand; blend- takes place, a negative impact on wear nology manager for Chevron Oronite ing facilities are being stressed to gener- tendencies may occur. This issue could in Richmond, Calif., sees VI improver ate all of the test oils needed; demands

manufacturers/suppliers or end-users of lubricants and lubricant-related products. 23 on technical staff are at all-time highs fuel economy and enabling GDI/TGDI other properties such as oxidation, and the investment required to accom- engines. Second generation dexos1, deposit and sludge control and wear plish all of this is perhaps the highest which contains 13 tests, sets higher performance.” seen by the lubricants industry.” standards for fuel economy and du- Tung believes that GM sees the new Tung provides a perspective about rability performance than the current dexos1 specification as a benefit to the how little time additive companies may dexos1. industry by allowing additive and oil have to develop new formulations once Haffner expresses concern that the companies to start formulating engine precision matrix studies are completed. lubricants industry may have to refor- oils around LSPI prevention and fuel economy. In addition, this new GM specification will stimulate all additive and petroleum companies to accelerate The proposed ILSAC GF-6 specification will enable a new preparations for the upcoming ILSAC GF-6 specification. level of performance for passenger car engine oils in the Davis ideally states that desire of era of efficiency. most in the lubricants industry re- garding GF-6 and dexos1. He says, “Although GF-6 and dexos1 have different performance criteria, most of He says, “The most difficult issue for mulate GF-6 products again once sec- the lubricants industry would like to the lubricants industry to develop new ond generation dexos1 is introduced. develop one engine oil that meets both additive technologies for GF-6 and He says, “Considering the qualification specifications.” PC-11 at the same time is about the and licensing protocols introduced by The automotive lubricants industry uncertainty of final performance limits GM, most products will probably re- is now facing an unprecedented de- for both specifications until December quire new formulations which will im- mand to develop products for two new 2016 or even later after all precision pact logistics. With GF-6 only 18-24 industry-wide specifications and a third matrix jobs’ verification. Additive com- months after the planned introduction specification for a specific OEM. Addi- panies only have approximately a half- of second generation dexos1, PCMOs tive suppliers will need to develop new year time frame to develop a new for- may need to be reformulated again to additives and formulation approaches mulation to meet GF-6 requirements. meet GF-6.” to meet specification deadlines that In addition, all performance limits for Parsons adds, “Formulators must are timed to be in close proximity to all engine sequence tests are still not develop products to meet next gen- each other. The hope is that by using a well established. Further complicating eration dexos without knowing how strong knowledge base and efficiently the process is that performance limits or whether they will necessarily link using its resources, the lubricants in- for GF-6A and GF-6B have not been to GF-6 once it is introduced. Since dustry will be able to meet the strict established as their own performance dexos1 is more than one year in ad- timelines for all three specifications. limits are still being debated.” vance of GF-6, short-term priority must be given to dexos.” DEXOS1 Tung discusses the challenge of Neil Canter heads his own The dexos1 specification is the auto- meeting GM’s new engine oil specifica- consulting company, Chemical Solutions, in Willow Grove, Pa. maker’s way of ensuring the right oil tion. He says, “During this spring at the Ideas for Tech Beat can be is used to enable optimum vehicle per- Fuels & Lubes Asia Conference, GM submitted to him at formance, particularly with GDI and manager Angela Willis made an out- [email protected]. TGDI technology. standing presentation on the perspec- The second generation dexos1 spec tive of GM on fuel economy and engine REFERENCES includes more tests and greater per- oils. She told the audience, “Second formance demands far beyond current generation dexos1 builds in several 1. Van Rensselar, J. (2013), “PC-11 and GF-6: New engines drive ILSAC industry specifications. Adding performance improvements, especially change in oil specs,” TLT, 69 (1), to the demands of managing upgrades around LSPI and fuel economy.” pp. 30-38. to GF-6 and PC-11 is the mandatory Willis emphasized that GM has in- 2. McCarthy, S. (2014), “The future of transition to GM’s second generation troduced a vehicle fuel economy test heavy duty diesel engine oils,” TLT, dexos1 in August 2016, ahead of the that is a new concept for North Ameri- 70 (10), pp. 38-50. first license for GF-6 and PC-11. can engine oil specifications. The chal- 3. Canter, N. (2013), “Fuel economy: Birze says, “Much of the signifi- lenge is to have formulations that pro- The role of friction modifiers and VI improvers,” TLT, 69 (9), pp. 14- cance of second-generation dexos1 vide top notch, LSPI and fuel economy 27. stems from its unprecedented focus on performance without compromising

24 • SEPTEMBER 2015 TRIBOLOGY & LUBRICATION TECHNOLOGY WWW.STLE.ORG