Patent ID: 8450253

Claim:
A lubricating oil composition comprising: (A) one type or a mixture of two or more types of mineral base oil having a 40° C. kinematic viscosity of from 5 to 15 mm 2 /s; and (B) one type or a mixture of two or more types of ester-based base oil having a 40° C. kinematic viscosity of from 3 to 25 mm 2 /s, a 0° C. kinematic viscosity of from 10 to 130 mm 2 /s and a viscosity index of 170 or greater, the 40° C. kinematic viscosity of the mixed base oil of (A) and (B) being 18 mm 2 /s or lower, the blend ratio of the ester-based base oil being from 0.58 to 80 percent by mass, and the 40° C. kinematic viscosity of the composition being from 4 to 23 mm 2 /s.