| abstract |
A lubricating oil composition which comprises 97 to 60 wt % of mineral oil having a dynamic viscosity at 100C of 2 to 50 cSt, a flow point (according to JIS K-2269) of not higher than -30C, and a viscosity index (according to JIS K-2283) of 70 or more and 3 to 40 wt % of a polyester. This composition is suitably used for lubrication of parts such as wet brakes or wet clutches of automatic transmissions, tractors, etc. This composition shows a proper viscosity at high temperatures and a low viscosity at low temperatures. Further, it has excellent friction properties, oxidation stability, and rubber seal resistance. |