RECONCILIATION OF DIFFERENCES IN THE RESULTS OF PUBLISHED SHORTFALL ANALYSES OF 1981 MODEL YEAR CARS

The failure of a vehicle to achieve its EPA mpg rating on the road is termed shortfall. Shortfall can be expressed in terms of either fuel economy (mpg) or fuel consumption (gpm). A vehicle achieving 25 mpg on the road but rated at 30 mpg in terms of the EPA 55/45 composite is said to show 16.7 percent shortfall in terms of mpg but 20 percent shortfall in terms of gpm. It can also be said that the EPA estimate overstates actual mpg performance by 20 percent. Specifically, this report has dealt with points of agreement and disagreement of GM, Ford, DOE and EPA with regard to: (1) overall shortfall, (2) mpg dependence of shortfall, (3) technology dependence of shortfall, and (4) model-year trends in shortfall. Our summary and conclusions with regard to each of these concerns are presented.

  • Corporate Authors:

    Energy and Environmental Analysis, Incorporated

    1111 North 19th Street
    Arlington, VA  United States  22209
  • Publication Date: 1983-9

Media Info

  • Pagination: 89 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00390044
  • Record Type: Publication
  • Source Agency: Energy Research Abstracts
  • Report/Paper Numbers: DOE/PE/70045-T20
  • Contract Numbers: AC01-78PE70045
  • Files: TRIS
  • Created Date: Nov 30 1984 12:00AM