| 摘要 |
PROBLEM TO BE SOLVED: To provide a lubricant composition which is excellent in fuel consumption saving and low-temperature viscosity and can satisfy both of fuel consumption saving and low-temperature viscosity at≤-35°C while maintaining high-temperature high-shear viscosity without using synthetic oil such as polyolefin type base oil and ester type base oil, and low-viscosity mineral oil type base oil. SOLUTION: The lubricant composition comprises: a lubricant base oil having dynamic viscosity at 100°C of 1 to 10 mm<SP>2</SP>/s, a %C<SB>p</SB>of 70 or more and a %C<SB>A</SB>of 5 or less; and a viscosity index improving agent of which the weight average molecular weight is 100,000 or more and the ratio of the weight average molecular weight to PSSI is 0.8×10<SP>4</SP>or more, of 0.1 to 50 mass% on the basis of the whole amount of lubricant composition, wherein the dynamic viscosity at 100°C is 4 to 9.3 mm<SP>2</SP>/s and HTHS viscosity at 150°C is 2.7mPa s or more. COPYRIGHT: (C)2009,JPO&INPIT |
