GEAR OIL COMPOSITION

摘要

The present invention provides a gear oil composition having fuel saving performance and providing gears or bearings with sufficient durability and comprising a base oil comprising a blend of (A) a mineral lubricating base oil having a 100°C kinematic viscosity of 2 to 6 mm 2 /s, a %CA of 0.5 or less and a tertiary carbon content of 7% or more blended and (B) a solvent-refined mineral lubricating oil having a 100°C kinematic viscosity of 10 to 70 mm 2 /s in an amount of 2 to 40 percent by mass on the total base oil composition mass basis; (D) zinc dialkyldithiophosphate in an amount of 0.02 to 0.5 percent by mass on the zinc amount basis; and (E) an alkaline earth metal detergent having a base number of 100 mgKOH/g or greater in an amount of 0.1 to 0.5 percent by mass on the metal amount basis, on the gear oil composition mass basis.