Patent ID: 7838473

Claim:
A lubricating oil composition having a sulfur content of up to about 0.3 wt. %, a phosphorus content of from about 0.02 to about 0.08 wt. %, a sulfated ash content of up to about 0.80 wt. % and a total base number of about 8 to 9 mg KOH/g, which lubricating oil composition comprises an admixture of: (a) a major amount of oil of lubricating viscosity selected from one or more of the group consisting essentially of, Group II, Group III, Group IV, Group V and synthetic ester base stock oils; (b) overbased detergent in such amount so as to provide a TBN of from about 5.3 to about 7.3 mg KOH/g to the lubricating oil composition, which overbased detergent comprises from about 0.4 to about 1.0 wt. % of overbased magnesium-containing lubricating oil detergent having a TBN of 200 to 500 and an amount of overbased calcium salicylate detergent providing said lubricating oil composition with the remainder of the from about 5.3 to about 7.3 mg KOH/g TBN provided by overbased detergent; and (c) an ashless dispersant present in an amount of at least about 2.5 to about 4 wt. % and providing the lubricating oil composition with a nitrogen content of from about 0.05 to about 0.1 wt. %.