Patent ID: 8901051

Claim:
A lubricating composition comprising an API Group II or Group III oil of lubricating viscosity and 0.2 wt % to 0.5 wt % of an N-substituted malimide, or mixtures thereof, and wherein the N-substituted malimide is represented by formula (1): wherein R is a hydrocarbyl group containing 8 to 20 carbon atoms, with the proviso that when the N-substituted malimide comprises molecules with a hydrocarbyl group of less than 8 carbon atoms, then the N-substituted malimide is in the form of a mixture of N-substituted malimides and the hydrocarbyl groups in said mixture have an average total number of carbon atoms of at least 6, and wherein the lubricating composition is characterised as having (i) a sulphur content of 0.5 wt % or less, (ii) a phosphorus content of 0.1 wt % or less, and (iii) a sulphated ash of 1.5 wt % or less.