Thread: oil lube language
View Single Post
  #4  
Old 09-24-2012, 04:16 AM
ckau's Avatar
ckau ckau is offline
Heavy Contributor
  

Join Date: Dec 2009
Location: central North Carolina
Posts: 915
Default
S- indicate Spark/ignition motors.
F- is a designation for some earlier type motors with smog systems. The F indicates some additives have been removed from the oil that can harm the smog system.
Reply With Quote