Patent ID: 7371710

Claim:
A lubricating oil composition which comprises a lubricating base oil having a kinematic viscosity of 1 to 10 mm 2 /s at 100° C., (A) a boron-containing ashless dispersant in an amount of 0.02 to 0.1 percent by mass in terms of boron, based on the total mass of the composition, (B) an alkaline earth metal-based detergent with a base number of 0 to 500 mgKOH/g in an amount of 0.01 percent by mass or more in terms of alkaline earth metal, based on the total mass of the composition, and (C) an alkali metal borate or a hydrate thereof in an amount of 0.002 to 0.06 percent by mass in terms of boron, based on the total mass of the composition.