Abstract: A lubricating oil composition comprising: (A) an oil of lubricating viscosity in a major amount; (B) an oil-soluble polymeric additive component (B) as an additive in a minor amount. The lubricating oil composition exhibits enhanced oxidative stability when used to lubricate a spark-ignited or compression-ignited internal combustion engine which is fuelled with a biofuel.

Abstract: A lubricating oil composition comprising: (A) an oil of lubricating viscosity in a major amount, comprising a Group III base stock; (B) as an additive component in a minor amount, a viscosity index improver comprising a linear or star-shaped polymer which is derivable, at least in part, from the polymerisation of one or more conjugated diene monomers; and, wherein the lubricating oil composition is contaminated with at least 0.3 mass %, based on the total mass of the lubricating oil composition, of a biofuel or a decomposition product thereof and mixtures thereof.

Abstract: A crankcase lubricating oil composition comprising: (A) an oil of lubricating viscosity in a major amount; (B) as an additive component in a minor amount, an oil-soluble metal salt of a dithiophosphoric acid; (C) as an additive component in a minor amount, an oil-soluble carbodiimide compound; and, wherein the lubricating oil composition is contaminated with at least 0.3 mass %, based on the total mass of the lubricating oil composition, of a biofuel or a decomposition product thereof and mixtures thereof.