Patent ID: 8778855

Claim:
A lubricating oil composition suitable for a continuously variable transmission, comprising: a lubricating base oil; an overbased calcium sulfonate having a base number of 280 mgKOH/g to 500 mgKOH/g; and orthophosphate of 0.03-mass % to 3 mass % of a total amount of the lubricating oil composition, wherein the lubricating base oil is at least one of a mineral oil and a synthetic oil, wherein the lubricating base oil has a saturated hydrocarbon component of 90 mass % or more, a sulfur component of 0.03 mass % or less and the viscosity index of 100 or more, wherein the overbased calcium sulfonate is present in a calcium concentration of 300 mass ppm to 600 mass ppm of the total amount of the lubricating oil composition, the overbased calcium sulfonate is present in a calcium concentration of 0.5 to 1.2 times of a total phosphorous concentration of the lubricating oil composition, wherein the overbased calcium sulfonate is a combination of a plurality of overbased calcium sulfonates having different base numbers so that the overbased calcium sulfonate exhibits a total base number of 280 mgKOH/g to 500 mgKOH/g, and each of the plurality of overbased calcium sulfonates has different base numbers ranging from 280 mgKOH/g to 500 mgKOH/g.