Patent ID: 8030255

Claim:
A lubricating oil composition comprising: (A) a base oil with a kinematic viscosity at 100° C. of 1 to 8 mm 2 /s, a pour point of −15° C. or lower an aniline point of 100° C. or higher, and a viscosity index of 100 to 135, the saturates of the base oil containing 40 to 57 percent by mass of paraffins and 43 to 60 percent by mass of naphthenes, wherein a mass ratio of one ring naphthenes to two to six ring naphthenes is 0.77 or less, as the main component; and on the basis of the total amount of the composition: (B) 0.005 to 0.4 percent by mass of a metallic detergent; (C) 0.005 to 0.2 percent by mass in terms of nitrogen of a succinimide-type ashless dispersant; (D) 0.005 to 0.2 percent by mass in terms of phosphorus of a phosphorus-containing anti-wear agent; and (E) 0.01 to 20 percent by mass of a viscosity index improver with a weight average molecular weight (Mw) of 50,000 or greater; wherein a viscosity index of the composition is 160 or greater.