Provided is a lubricating oil for continuously variable transmissions characterized by that used as a base oil are a synthetic oil I having the following properties:
(a) a traction coefficient at 120° C. is 115% or more of that of 2,4-dicyclohexyl-2-methylpentane,
(b) a viscosity at −40° C. is not higher than a viscosity (260 Pa·s) of 2,4-dicyclohexyl-2-methylpentane and
(c) a viscosity index is 65 or higher and a synthetic oil II having a viscosity of 1 Pa·s or lower at −40° C. and that the above base oil has a specific property.
The above lubricating oil is a lubricating oil for continuously variable transmissions which has a high traction coefficient even at high temperature and is endowed with a good low temperature fluidity and which is suited as a lubricating oil for continuously variable transmissions for automobiles.
提供的连续变速器润滑油的特点是使用以下性质的合成油I作为基础油:(a)在120℃下的牵引系数是2,4-二环己基-
2-甲基戊烷的115%或更高,(b)在-40℃下的粘度不高于2,4-二环己基-
2-甲基戊烷的粘度(260 Pa·s),(c)粘度指数为65或更高,以及一种在-40℃下粘度为1 Pa·s或更低的合成油II,上述基础油具有特定性质。上述润滑油是一种连续变速器润滑油,即使在高温下也具有高牵引系数,并具有良好的低温流动性,适用于汽车连续变速器润滑油。