LUBRICANT OIL COMPOSITION FOR CONTINUOUSLY VARIABLE TRANSMISSION

PROBLEM TO BE SOLVED: To provide a lubricant oil composition for a continuously variable transmission having low viscosity and a high viscosity index, satisfactory shear stability and a long fatigue life. SOLUTION: The lubricant oil composition for a continuously variable transmission is formed by compounding, with specified compounding quantities, (A) a mineral oil or a PAO (Poly-α-Olefin) having ≤0.03 mass% sulfur content and 1.5 to 3 mm2/s kinematic viscosity at 100°C, (B) a mineral oil or a PAO having ≤0.03 mass% sulfur content and 5.5 to 8 mm2/s kinematic viscosity at 100°C, (C) a PAO having 30 to 400 mm2/s kinematic viscosity at 100°C and (D) a polymethacrylate having mass average molecular weight of 10,000 to 40,000, wherein the total quantity of the component (C) and the component (D) is 19 mass% or more, and the lubricant oil composition for a continuously variable transmission has 5.5 to 6.5 mm2/s kinematic viscosity at 100°C and ≤680 mm2/s kinematic viscosity at -20°C. COPYRIGHT: (C)2011,JPO&INPIT