| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a lubricant composition with which dynamic viscosities at 40°C and 100°C and HTHS viscosity at 100°C can be sufficiently reduced while retaining the HTHS viscosity at 150°C, and the rise of the friction coefficient in a boundary lubricating area can be sufficiently suppressed, and which has excellent fuel efficiency.SOLUTION: The lubricant composition comprises: a lubricant base oil having a kinetic viscosity at 100°C of 1-20 mm/s; (A) a viscosity index improver having a ratio M1/M2 of 0.20 or more, in which M1 is the total area of peaks between chemical shift 36-38 ppm to the total area of all peaks and M2 is the total area of peaks between chemical shift 64-66 ppm to the total area of all peaks, in a spectrum obtained byC-NMR; (B) a friction regulating agent; and (C) an overbased metal salt obtained by performing overbasing of an oil-soluble metal salt with an alkaline earth metal borate.</p> |
