Additive Concentrates for the Formulation of Lubricating Oil Compositions

A lubricant additive concentrate containing (i) dispersant that is the polybutenyl succinimide reaction product of a polyamine and polybutenyl succinic anhydride (PIBSA) derived from polybutene having a number average molecular weight (Mn) of from about 1300 to about 2500 daltons and a terminal vinylidene content of at least about 50% and maleic anhydride via an ene maleation process; (ii) overbased magnesium colloidal detergent having a total base number (TBN) of from about 300 to about 900 mg KOH/g; and (iii) organic friction modifier selected from hydroxyalkyl alkyl amines of C14 to C24 hydrocarbons, at least one hydroxyalkyl alkyl ether amines of C13 to C24 hydrocarbons, at least one alkyl ester amine derived from triethanol amine having a C13 to C24 hydrocarbyl substituent, at least one non-basic, fatty acid amide, or a mixture thereof; wherein the combined mass % of dispersant (i) and overbased magnesium colloidal detergent (ii) in said concentrate is from about 15 to about 50 mass %: the mass ratio of (i):(ii) is from about 1:1 to about 6:1; and the concentrate contains from about 2 to about 10 mass % of organic friction modifier (iii); the remainder of the concentrate being composed of base oil and additives other than dispersant (i), overbased magnesium colloidal detergent (ii) and organic friction modifier (iii).