SELECTING COMPRESSION RATIO FOR OPTIMUM FUEL ECONOMY WITH EMISSION CONSTRAINTS

An experimental program is described for selecting engine compression ratio to optimize vehicle fuel economy, with imposed emission constraints. A method was developed to relate quantiatively the results of single cylinder engine experiments to vehicle emission tests results. Engine and vehicle experiments were conducted to validate the method. This study concludes that compression ratio optimization is determined primarily by hydrocarbon emission restrictions. Projections for a 1975 400 CID engine in a 5000 pound vehicle demonstrate that the traditional relationship between fuel economy and compression ratio is reversed below CVS-CH HC levels in the range of 1.0-1.5 gm/mile. /GMRL/

  • Corporate Authors:

    Society of Automotive Engineers

    400 Commonwealth Drive
    Warrendale, PA  USA  15096
  • Authors:
    • BAKER, R E
    • Daby, E E
    • Pratt, J W
  • Publication Date: 1977

Media Info

  • Pagination: 47 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00158397
  • Record Type: Publication
  • Report/Paper Numbers: SAE 770191
  • Files: TRIS
  • Created Date: Dec 8 1977 12:00AM