LOW-ASH ENGINE OIL COMPOSITION

摘要

A low-ash engine oil composition which, despite the low ash content, has engine-cleaning performance which enables the composition to pass a severe detergency test for diesel engine oils. It further has excellent mileage-saving performance. The low-ash engine oil composition has a sulfated ash content of 0.6 mass% or lower, and is characterized by comprising: a lube base oil having a %C_A of 2 or lower, a dynamic viscosity at 40°C of 25 mm²/s or lower, and a viscosity index of 120 or higher; a viscosity index modifier contained in such an amount that the composition has a viscosity index of 160 or higher; and (A) a metallic detergent having a metal ratio of 3 or lower and/or (B) a sulfur-free phosphorus compound.