Patent ID: 8580719

Claim:
A lubricating oil composition comprising: a base oil comprising at least one oil selected from the group consisting of a mineral oil, a synthetic oil, and a mixture thereof; 0.029-0.049 wt. % of polyisobutylene, based on an amount of a resin component in the lubricating oil composition, wherein the polyisobutylene has a weight-average molecular weight of 500,000 or higher; and 0.065-0.585 wt. % of a viscosity index improver, based on an amount of a resin component in the lubricating oil composition, wherein the viscosity index improver comprises at least one polymer selected from the group consisting of a polymethacrylate, a styrene-isoprene copolymer, and an ethylene-α-olefin copolymer, and wherein the polymer has a weight-average molecular weight of 100,000-800,000, wherein the lubricating oil composition has a kinematic viscosity of 35 mm 2 /s or lower at 40° C. and a viscosity index of 120-300.