Patent ID: 7056871

Claim:
A lubricating oil composition comprising: (a) a major amount of an oil of lubricating viscosity; (b) from about 0.25 to about 3.6 wt % organic sulfur-containing extreme pressure additive; (c) from about 0.3 to about 1.5 wt % amino phosphorus compound; (d) from about 0.01 to about 1.2 wt % alkyl or alkenyl succinic anhydride, wherein the alkyl or alkenyl group has a number average molecular weight of about 176 to about 550; and (e) from about 0.15 wt % to about 0.25 wt % thiadiazole, wherein the thiadiazole does not contain a polycarboxylate moiety and the amount of dimercaptothiadiazole present in the thiadiazole is from about 0.1 wt % to about 10 wt %.