General Motors Corporation has recently asserted that the test fuel used at the Environmental Protection Agency (EPA) Motor Vehicle Emissions Lab. (MVEL) has varied in energy density and carbon content since 1975. General Motors has subsequently requested that a Corporate Average Fuel Economy (CAFE) correction be granted to account for these variations in fuel properties. General Motors has submitted data demonstrating that the test fuel used by GM has varied since 1975 . Since EPA and GM obtain fuel from the same sources it is probable that the EPA test fuel has also varied in a similar fashion. If so, this is a change which would systematically affect the measured fuel economy of test vehicles and hence corporate average fuel economies (CAFE). The change is similar to previous test procedure changes for which CAFE corrections have been proposed. This report develops a simple correction based on the energy content per unit carbon of the fuel. The corrrection proposed by GM is also discussed, as is the problem of limited available data on the test fuels.

  • Corporate Authors:

    Environmental Protection Agency

    Dallas, TX  United States  75202
  • Authors:
    • Thompson, G D
  • Publication Date: 1984-9

Media Info

  • Pagination: 16 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00450063
  • Record Type: Publication
  • Source Agency: Energy Research Abstracts
  • Files: TRIS
  • Created Date: Aug 27 2004 8:55PM