Technological Improvements to Automobile Fuel
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-_ . _I I I. I*. -\ r -1 ’ ,, . f ._,. .. 1 REPORT NO. DOT-TSC-OST-74-39. IIA I I Ii ’i ‘ TECHNOLOGICAL IMPROVEMENTS I 1, r TO AUTOMOBILE FUEL CONSUMPTION ~ Volume II A: Sections 1 through 23 i- I -- - I’ r C. W, Coon et a1 \ ’ j *I DECEMBER 1974 -”= I 1 FINAL REPORT iI - I DOCUMENT IS AVAILABLE TO THE PUBLIC ~ This document is THROUGH THE NATIONAL TECHNICAL ~ PUBLICLY INFORMATION SERVICE, SPRINGFIELD, ,- I RELEASABLE VIRGINIA 22161 1 I ” <._ I I I .- - Prepared- for ! U I S I DEPARTMENT OF TRANSPORTAT 1014 OFFICE THE SECRETARY Office of the AssistantOF Secretary for Systems i i Development and Technology ’ Washington DC 20590 and U I SI EfJVI ROFJrlENTAL PROTECTIOM AGENCY I Ann Arbor MI 48105 1 ! I eflSl”RlBU”r0N OF THIS DOCUMENT IS CINC\MITED i ." i NOT I CE This document is disseminated under sponsorship of the Department of Transportation and Environmental Protection Agency in the interest of {nformation exchange. The United States Government assumes no for liability its contents or use thereof.I/ I ~ NOTICE The United States Government does not jlendorse products ' or manufacturers. Trade or manufactu5ers' names appear herein solely because they are /[considered essential to the object of this report. I ll > ': DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. Technical Report Documentation Page 1. Report No. 2 Government Accession No. 3. Recipient's Catalog No. DOT-TSC-OST-74-39.11A 5. Report Dote December 197 4 6. Performing Organization Code 8. Performing Orgonizotion Report No. DOT-TSC-OST-74-39,IIA 10. Work Unit NO. (TRAIS) 0S514/R5523 11. Contract or Grant No. DOT-TSC-628 13. Type of Report and Period Covered Final Report June 1973 -January 197 4 14. Sponsoring Agency Code : of Transportation Transportation Systems Center *Under Contract to: Kendall Square Cambridge -MA 02142 16. Abstract This report is a preliminary survey of the technological feasi- bility of reducing ,the fuel consumption of automobiles. The study uses as a reference information derived from literature, automobile industry contacts, and testing conducted as part of the program requirements. The design changes, which are recommended for the pur- pose of maximizing fuel economy, have been derived after lengthy reviek against a series of constraints including regulatory requirements, technical feasibility, and cost effectiveness. Several possible technological improvements are identified, documented, and evaluated with respect to fuel economy. Results are reported as percentage improvement in fuel economy by comparison with 1973 model year vehicles. The effect of vehicle emission control systems is considered in the evaluation procedure. The most promising individual improvements are incorporated into three synthesized vehicle designs, and the projected fuel economy improvement for these vehicles is reported. The status of the technology reported is that available in the time period of July 1973 to January 1974. Volume I1 consists of two parts, Volume I1 A and Volume I1 B. 18. Distribution Statement 17. Key Words Automobiles , Fuel Economy, Powerplants, Transmissions, Drive DOCUMENT IS AVAILABLE TO THE PUBLIC Trains, Tires, Accessories THROUGH THE NATIONAL TECHNICAL INFORMATION SERVICE, SPRINGFIELD, Aerodynamics, Weight, Fuel VIRGINIA 22161 Consumption, Innovations 19. Security Clossif. (of this report) 20. Security Classif. (of this page) 21. No. of Pones 22. Price 2321 Unclassified Unclassified - ._~ form DOT F 1700.7 (8-72) Reproduction of completed page authorized 1 PREFACE The transportation sector of the U.S. economy accounts for approximately 25 percent of the total energy demand, predominately in the form of petroleum fuels. The Government has been actively engaged in reviewing the technological and institutional actions that can be taken to reduce our transportation energy demand. One such effort is the preliminary study covered in this report on the technological feasibility of improved fuel economy in auton~obiles. The work described in this report was performed by Southwest Research Institute for the U.S. Department of Transportation and the US. Environmental Protection Agency. The project was monitored by the Power and Propulsion Branch, Mechanical Engineering Division, Transportation Systems Center, U.S. Department of Transportation. The technical monitor for the project was H. Gould. The authors recognize the timely significance of this study, and despite warnings to the con- trary, information may be taken out of context. For these reasons, the report has been written in an instructive fashion to acquaint the uninitiated reader with facts about automobile design. Hope- fully, this instruction will nullify the majority of inisconceptions and provide insight into an exceed- ingly complex issue. This work does not address the overall automobile transportation energy problem, but it is directed to one of the major components of the American automobile market-the ‘‘large’’ automo- bile. Specifically, this study is concerned with cars of the 4300- and 3300-lb curb weight classes. These vehicles are frequently identified by Federal Test Procedure inertia weight class with cor- responding values of 3500 and 4500 lb. The status of the technology reported is that available in the time period of July 1973 to January 1974. iii b The work covered in this report represents approximately a three-man year level of effort and was conducted over a six-month period. The goals ofthe project are ambitious, and the effort of each member of the project team was vital to the final product. Space does not permit the listing of all participants. but major efforts were contributed by: Dr. C. W. Coon, Senior Research Engineer B. C. Dial, Senior Research Engineer Roger Hemion, Institute Scientist R. W. H~tll,Senior Research Engineer K. J. Mathis, Research Engineer Car It o n M o rr is0 n , Techn i cian Lynn Rhymes, Research Engineer C. D. Wood, Manager, Energy Conversion Systems S. W. Seale, Research Analyst To in Stet t ler . Technician Clifford Reeh, Technician H. 0. Woller. Senior Technician John W. Colburn. Jr., Project Manager b iv ................................. .. TABLE OF CONTENTS Volume IIA 1. INTRODUCTION .......................... 1 2. AUTOMOBILE SYSTEMS AND OPERATIONAL REQUIREMENTS: INTERRELATIONSHIPS INFLUENCING ECONOMY ............. 5 3. COMPUTATION OF VEHICLE FUEL ECONOMY .............. 13 4 . TEST PROGRAM DESCRIPTION AND RESULTS .............. 19 Accessory Power Tests ......................... 19 Road Tests .............................. 'I LA-4 Chassis Dynamometer Tests .................... '0 Engine LoadISpeed BSFC Tests ..................... 3' 5. THE COST TO OWN AND OPERATE AN AUTOMOBILE ........... 37 Methodology for the Analysis of the Cost to Own and Operate an Automobile .... 37 Analysis of the Estimated Cost to Own and Operate an Automobile ........ 41 6 . CONSIDERATIONS IN PREDICTING PREPRODUCTION LEAD TIME FOR INCORPORATION OF FUEL ECONOMY INNOVATIONS ........... 47 Introduction ............................. 47 Product Development Lead Time ..................... 47 7. FUEL ECONOMY OF CARBURETED SPARK-IGNITION ENGINES ....... 51 General ............................... 51 Theoretical Cycle Efficiency ....................... 51 Factors Affecting Actual Engine Performance ................. 52 . > 8 . EXHAUST EM ISSI ONS 0 F AUTOMOTIVE SPAR K-lG N ITI ON CARBURETED ENGINES ........................ 61 General ............................... 61 Source of Exhaust Emissions ....................... 61 Effect of Engine Variables Upon Emissions .................. 62 Emission Control Systems ........................ 66 Conventional Automobile Exhaust Emissions and the Federal Emission Standards ... 68 V TABLE OF CONTENTS (Cont'd) Voluae I1 A (Cont'd) .Page 9. EMISSION CONTROL HARDWARE .......... 73 Positive Crankcase Ventilation ....................... 73 Lean Mixture Operation ......................... 73 Retarded Spark ............................ 74 Idle Stop Solenoid ........................... 75 Choke Heating Element ......................... 76 Heated Inlet Air System ......................... 76 Exhaust Gas Recirculation (EGR) ..................... 76 Air Injection ............................. 76 Evaporative Emission Control ....................... 76 Exhaust Reactors ............................ 78 10. TURBOCHARGED SPARK.lGN1TED. CARBURETED ENGINE ......... 81 Concept ............................... 81 Performance Evaluation Procedure ..................... 82 Results ................................ 84 Exhaust Emissions ........................... 87 Evaluation .............................