| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-viscosity lubricating composition of less than 2.6 mPa s in HTHS viscosity at 150°C, sufficiently lowered in dynamic viscosity at 40°C and 100°C and HTHS viscosity at 100°C, and capable of sufficiently suppressing the rise of coefficient of friction in boundary lubricating area, thus excellent in fuel economy saving property.SOLUTION: A lubricating oil composition comprises: a lubricating base oil of 1-5 mm/s in dynamic viscosity at 100°C, (A) a viscosity index improving agent of 400,000 or less in weight-average molecular weight (Mw) and 20 or less in PSSI, (B) a perbasic metallic cleaning agent of 3.4 or less in metal ratio, and (C) a friction adjuster, wherein its HTHS viscosity at 150°C is less than 2.6 mPa s. |
