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Consensus Study Report


The light-duty vehicle fleet is expected to undergo substantial technological changes over the next several decades. New powertrain designs, alternative fuels, advanced materials and significant changes to the vehicle body are being driven by increasingly stringent fuel economy and greenhouse gas emission standards. By the end of the next decade, cars and light-duty trucks will be more fuel efficient, weigh less, emit less air pollutants, have more safety features, and will be more expensive to purchase relative to current vehicles. Though the gasoline-powered spark ignition engine will continue to be the dominant powertrain configuration even through 2030, such vehicles will be equipped with advanced technologies, materials, electronics and controls, and aerodynamics. And by 2030, the deployment of alternative methods to propel and fuel vehicles and alternative modes of transportation, including autonomous vehicles, will be well underway. What are these new technologies - how will they work, and will some technologies be more effective than others?

Written to inform The United States Department of Transportation's National Highway Traffic Safety Administration (NHTSA) and Environmental Protection Agency (EPA) Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emission standards, this new report from the National Research Council is a technical evaluation of costs, benefits, and implementation issues of fuel reduction technologies for next-generation light-duty vehicles. Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles estimates the cost, potential efficiency improvements, and barriers to commercial deployment of technologies that might be employed from 2020 to 2030. This report describes these promising technologies and makes recommendations for their inclusion on the list of technologies applicable for the 2017-2025 CAFE standards.


Suggested Citation

National Research Council. 2015. Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles. Washington, DC: The National Academies Press.

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Publication Info

466 pages |  8.5 x 11 | 

  • Paperback:  978-0-309-37388-3
  • Ebook:  978-0-309-37391-3
Chapters skim
Front Matter i-xx
Summary 1-14
1 Introduction 15-22
2 Technologies for Reducing Fuel Consumption in Spark-Ignition Engines 23-96
3 Technologies for Reducing Fuel Consumption in Compression-Ignition Diesel Engines 97-128
4 Electrified Powertrains 129-166
5 Transmissions 167-206
6 Non-Powertrain Technologies 207-244
7 Cost and Manufacturing Considerations for Meeting Fuel Economy Standards 245-262
8 Estimates of Technology Costs and Fuel Consumption Reduction Effectiveness 263-306
9 Consumer Impacts and Acceptance Issues 307-336
10 Overall Assessment of CAFE Program Methodology and Design 337-368
Appendix A: Statement of Task 369-370
Appendix B: Committee Biographies 371-375
Appendix C: Presentations and Committee Meetings 376-378
Appendix D: Ideal Thermodynamic Cycles for Otto, Diesel, and Atkinson Engines 379-379
Appendix E: SI Engine Definitions and Efficiency Fundamentals 380-380
Appendix F: Examples of Friction Reduction Opportunities for Main Engine Components 381-382
Appendix G: Friction Reduction in Downsized Engines 383-383
Appendix H: Variable Valve Timing Systems 384-385
Appendix I: Variable Valve Lift Systems 386-389
Appendix J: Reasons for Potential Differences from NHTSA Estimates for Fuel Consumption Reduction Effectiveness of Turbocharged, Downsized Engines 390-392
Appendix K: DOE Research Projects on Turbocharged and Downsized Engines 393-394
Appendix L: Relationship between Power and Performance 395-395
Appendix M: HCCI Projects 396-400
Appendix N: Effect of Compression Ratio of Brake Thermal Efficiency 401-401
Appendix O: Variable Compression Ratio Engines 402-403
Appendix P: Fuel Consumption Impact of Tier 3 Emission Standards 404-405
Appendix Q: Examples of EPA's Standards for Gasoline 406-406
Appendix R: Impact of Low Carbon Fuels to Achieve Reductions in GHG Emissions (California LCFS 2007 Alternative Fuels and Cleaner Fossil Fuels CNG, LPG) 407-408
Appendix S: NHTSA's Estimated Fuel Consumption Reduction Effectiveness of Technologies and Estimated Costs of Technologies 409-419
Appendix T: Derivation of Turbocharged, Downsized Engine Direct Manufacturing Costs 420-421
Appendix U: SI Engine Pathway NHTSA Estimates Direct Manufacturing Costs and Total Costs 422-425
Appendix V: SI Engine Pathway NRC Estimates Direct Manufacturing Costs Alternative Pathway, Alternative High CR with Exhaust Scavenging, and Alternative EVAS Supercharger 426-433
Appendix W: Technologies, Footprints, and Fuel Economy for Example Passenger Cars, Trucks, and Hybrid Passenger Cars 434-437
Appendix X: Full System Simulation Modeling of Fuel Consumption Reductions 438-441
Appendix Y: Acronym List 442-446

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