| abstract |
A heavy duty diesel engine lubricating oil composition comprising, or made bynadmixing:n (A) a major amount of an oil of lubricating viscosity comprising at least 35 massn% of a Group III basestock, based on the mass of the oil of lubricating viscosity,nthat contains at most 0.03 mass % of sulfur, based on the mass of the basestock,nand that has a viscosity index of 120 or greater and has greater than or equal ton90 mass % saturates, based on the mass of said basestock; and (B) a minor amount of an additive composition comprising :n (i) a detergent composition; and (ii) one or more other additives; nwherein the oil composition has a cold cranking simulated viscosity, measurednaccording to ASTM D2602, of less than 7000 mPa.s at -25ºC and a sulfated ash,nmeasured according to ASTM D874, of less than 1.35 mass %, based on thenmass of the oil composition. The oil compositions provide improved pistonncleanliness of a heavy duty diesel engine. |