LUBRICATING OIL COMPOSITION FOR CONTINUOUSLY VARIABLE TRANSMISSION

摘要

Provided is a lubricating oil composition for a continuously variable transmission, said composition exhibiting a low viscosity whilst maintaining the viscosity required of the lubricating oil composition throughout a period of use in a mechanism, and maintaining a high friction coefficient between metals so as to ensure a high power-transmitting force provide the wet clutch friction characteristics and the shudder prevention properties required in a transmission. The composition also achieves improved fuel economy due to a low traction coefficient. In the composition, (B) a phosphorus compound, (C) a calcium salicylate and/or a calcium sulfonate, (D) a boron-modified ashless dispersant, and (E) a friction regulating agent are included, each at a specified amount, in a base-oil that has been adjusted so that the product (ECxV40) of the mass percent (EC(mass%)) of a saturated cyclic component, as based on the total base-oil mass, and the kinematic viscosity (V40(mm2/s)) at 40°C is equal to or less than 500, and the kinetic viscosity at 100°C is 3.6-4.1mm2/s. The lubricating oil composition has a kinematic viscosity at 100°C of 5.2-5.6mm2/s and a viscosity index of equal to or greater than 165.