Drive Cycle Powertrain Efficiencies and Trends Derived from EPA Vehicle Dynamometer Results

Vehicle manufacturers among others are putting great emphasis on improving fuel economy (FE) of light-duty vehicles in the U.S. market, with significant FE gains being realized in recent years. The U.S. Environmental Protection Agency (EPA) data indicates that the aggregate FE of vehicles produced for the U.S. market has improved by over 20% from model year (MY) 2005 to 2013. This steep climb in FE includes changes in vehicle choice, improvements in engine and transmission technology, and reducing aerodynamic drag, rolling resistance, and parasitic losses. The powertrain related improvements focus on optimizing in-use efficiency of the transmission and engine as a system, and may make use of what is termed downsizing and/or downspeeding. This study quantifies recent improvements in powertrain efficiency, viewed separately from other vehicle alterations and attributes (noting that most vehicle changes are not completely independent). A methodology is outlined to estimate powertrain efficiency for the U.S city and highway cycle tests using data from the EPA vehicle database. Comparisons of common conventional gasoline powertrains for similar MY 2005 and 2013 vehicles are presented, along with results for late-model hybrid electric vehicles, the Nissan Leaf and the Chevy Volt.

• Record URL:
  • https://doi.org/10.4271/2014-01-2562
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/19463995
• Supplemental Notes:
  • Abstract reprinted with permission of SAE International.
• Authors:
  • Thomas, John
• Conference:
  • SAE 2014 International Powertrain, Fuels & Lubricants Meeting
  • Location: Birmingham, United Kingdom
  • Date: 2014-10-20 to 2014-10-22
• Publication Date: 2014-10-13

Language

• English

Media Info

• Media Type: Web
• Features: References;
• Pagination: pp 1374-1384
• Serial:
  • SAE International Journal of Passenger Cars - Mechanical Systems
  • Volume: 7
  • Issue Number: 4
  • Publisher: SAE International
  • ISSN: 1946-3995
  • EISSN: 1946-4002
  • Serial URL: https://www.sae.org/publications/collections/content/E-JOURNAL-06/

Subject/Index Terms

• TRT Terms: Databases; Drag; Dynamometers; Fuel consumption; Light vehicles; Optimization; Power trains; Statistical trends
• Identifier Terms: U.S. Environmental Protection Agency
• Uncontrolled Terms: Drive cycles
• Geographic Terms: United States
• Subject Areas: Energy; Highways; Passenger Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 01639456
• Record Type: Publication
• Source Agency: SAE International
• Report/Paper Numbers: 2014-01-2562
• Files: TRIS, SAE
• Created Date: Jun 28 2017 2:38PM