FUEL CHARACTERISTICS AFFECT ECONOMY

The fuel consumption of motor vehicles is commonly expressed in terms of distance and unit volume. This does not provide an accurate indication unless the fuel's density is taken into account, since the heating value per unit volume increases with density. Of all the variations in fuel characteristics which affect economy, that of density is one of the most significant, i.e. ,1974 densities of some commercial gasolines were 0.68-0.77 kg/l (5.7-6.4 lb/gal) while during the winter of 1976-77 they were 0.69-0.78 kg/l (5.8-6.5 lb/gal). In the case of tests made using gasolines at the extremes of this range, fuel consumption differences of up to 7% could occur if no density correction were made. Indolene HO III is used as fuel for emission certification tests: 1974 variations for this gasoline were 0.731-0.745 kg/l (6.10-6.22 lb/gal). The maximum fuel consumption variation for the density change is about 1%. Thus, for accurate evaluations or comparisons of fuel economy, it should be measured using gasoline of a fixed density. Alternatively, it should be corrected for density, to refer all the results to those of a fixed density gasoline.

Media Info

  • Pagination: p. 54-55
  • Serial:
    • Automotive Engineering
    • Volume: 86
    • Issue Number: 6
    • Publisher: Society of Automotive Engineers
    • ISSN: 0098-2571

Subject/Index Terms

Filing Info

  • Accession Number: 00183250
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Dec 12 1978 12:00AM