Disclosed are lubricating oil compositions having improved anti-wear properties, comprising a major portion of a lubricating oil and an effective amount of an oil soluble additive combination comprising a basic zinc alkyl dithiophosphate having alkyl groups made from primary alcohols containing from about 6 to about 20 carbon atoms and a non-acidic lubricating oil anti-rust compound comprising a succinic anhydride substituted with an alkenyl group which has about 8 to about 50 carbon atoms reacted with an alcohol, an amine, or mixtures thereof.The zinc dithiophosphate is generally made from primary alcohol containing about 7 to about 12 carbon atoms and generally has a zinc to phosphorous ratio of about 1.15-1.5:1.