Patent attributes
A lubricating oil composition includes lubricating oil base oil, an organic molybdenum compound (A), zinc dialkyl dithiophosphate (B), at least one compound (C) selected from calcium sulfonate, calcium phenate, and magnesium sulfonate and having a base number of 230 mgKOH/g or more, and an ashless dispersant containing boron or a mixture of an ashless dispersant containing boron and an ashless dispersant containing no boron (D) in predetermined ratios, in which: a mass ratio (P/Mo) of the P content to the Mo content in the composition is 1.5 or more; a mass ratio (CaMg/Mo) of a total content of the Ca and Mg derived from the component (C) to the Mo content in the composition is 3 or more; and a mass ratio (B/N) between B and N derived from the component (D) in the composition is 0.5 or more. The lubricating oil composition of the present invention has a high static friction coefficient of wet clutch, has excellent frictional property in a power transmission mechanism, has excellent fuel saving property, and is suitably used for power transmission lubricating oil and engine lubricating oil.
