Lubricating oil composition for internal combustion engine

摘要

The present invention provides a lubricating oil composition for internal combustion engines which can reduce sufficiently the friction under mixed lubricating conditions and is excellent in fuel saving properties. The lubricating oil composition comprises (A) a base oil having a 100° C. kinematic viscosity of 2 to 8 mm2/s and an aromatic content of 10 percent by mass or less, (B) a metallic detergent having a metal ratio of 1.01 to 3.3 overbased with an alkaline earth metal borate, and (C) an organic molybdenum compound with a molybdenum concentration of 0.01 to 0.2 percent by mass on the basis of the total mass of the composition, and having a 100° C. HTHS viscosity of 5.5 mPa·s or lower.

主权项

1. An internal combustion engine lubricating oil composition comprising:
(A) a base oil having a 100° C. kinematic viscosity of 2 to 8 mm2/s and an aromatic content of 10 percent by mass or less, (B) a metallic detergent having a metal ratio of 1.01 to 3.3 overbased with an alkaline earth metal borate, and (C) an organic molybdenum compound with a molybdenum concentration of 0.01 to 0.2 percent by mass on the basis of the total mass of the composition, and having a 100° C. HTHS viscosity of 5.5 mPa-s or lower, wherein Component (B) has a mass ratio (MB1/MB2) of a metal content (MB1) derived from component (B) to a boron content (MB2) derived from Component (B) of greater than 2.9 to 20.