| abstract |
Provided is a lubricant oil composition for an internal combustion engine which is characterized by including a base oil having a viscosity index of 125 or higher and a Noack evaporation amount (250° C.×1 h) of 15% by mass or less, and, based on a total amount of the composition, from 0.1 to 10% by mass of (A) a C 2 to C 20 olefin polymer having a mass average molecular weight of 500 or more and 10,000 or less and/or (B) a polymeric compound having a mass average molecular weight of 10,000 or more and less than 100,000, wherein a content of (C) a polymeric compound having a mass average molecular weight of 100,000 or more is less than 1.0% by mass. The lubricant oil composition can, despite of its low viscosity, reduce noise during running, prevent fatigue damage such as gear pitting, reduce the consumption of the oil, and provide excellent fuel saving performance. |