EFFECT OF ENGINE OIL VISCOSITY ON LOW-TEMPERATURE CRANKING, STARTING, AND FUEL ECONOMY

The effect of engine oil viscosity on low-temperature cranking, starting, and vehicle fuel economy at low ambient temperatures was determined for vehicles equipped with four- and eight-cylinder engines. Oils ranging in SAE viscosity grade from 5W-20 to 30 were investigated at temperatures between - 40 and - 12 degree C. For both vehicles, engine cranking speed increased with decreasing cold cranking simulator (CCS) viscosity. This was reflected in easier starting with lower viscosity oils. In addition, the maximum viscosity for successful engine starting decreased as the temperature decreased. Fuel economy during engine warm-up increased with decreasing CCS viscosity, with the friction-modified oils investigated providing better fuel economy during warm-up and easier low-temperature starting.

  • Supplemental Notes:
    • Also published in HS-028 993 (SAE-SP-460), "The Relationship between Engine Oil Viscosity and Engine Performance, Pt. 5 and Pt. 6," Warrendale, Pennsylvania, 1980 p 53-70. Presented at SAE Congress and Exposition, Detroit, 25-29 February 1980.
  • Corporate Authors:

    Society of Automotive Engineers

    400 Commonwealth Drive
    Warrendale, PA  USA  15096
  • Authors:
    • Caracciolo, F
    • MCMILLAN, M L
  • Publication Date: 1979-6

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00303381
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Report/Paper Numbers: SAE 790728, HS-028 997
  • Files: HSL, TRIS
  • Created Date: Jan 30 1985 12:00AM