DICTIONARY OF AUTOMOTIVE TERMS - "Sf"

SF
  1. Acronym for Service factor
  2. An API classification for oil in gasoline engines in passenger cars and some trucks beginning with 1980 through 1989 models. Oils developed for this service provide increased oxidation stability and improved antiwear performance, and better protection against engine deposits, rust, and corrosion than the SE classified oil it replaced. It was replaced, in turn, by SG classified oil. These vehicles can benefit from the modern SM oils.
SF6
Abbreviation for sulfur hexafluoride
SFC
Acronym for Specific fuel consumption
SFI
Acronym for Sequential fuel injection