LUBRICATING OIL COMPOSITION

摘要

A lubricating oil composition for a heavy duty diesel engine comprises a bas e oil, at least 0.6 mass % of an ash-free antioxidant and an overbased magnesium-containing detergent. The detergent provides greater than 0.05 mass % Mg based on the mass of the composition. Bore polishing in the engine is reduced for a given level of exhaust gas ash production.