Comparison of EPA and On-Road Fuel Economy – Analysis Approaches, Trends, and Impacts

This paper is the latest in a series of reports on the U.S. Department of Energy’s (DOE) comparison of Environmental Protection Agency (EPA) fuel economy estimates and on-road fuel economy performance. Earlier reports described a variety of analysis techniques, described DOE’s expanding inuse fuel economy data base, and presented analysis of trends in EPA- versus on-road fuel economy.

The focus of this paper is the most recent additions to the data base (including data on light trucks and 1981 model-year cars), the development of DOE analysis techniques, and some of the more interesting trends revealed in this year’s analysis. Particular attention is given to model-year and vehicle-type differences, including driveline technology and model-type trends. The application of these results to improving fuel economy information programs and advertising for consumers is examined.

The paper concludes with an analysis of the effect of changing shortfall trends on automotive fuel consumption projections.