| 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. |