| 摘要 |
The lubricating oil composition of the invention comprises a lubricating base oil with a kinematic viscosity at 100°C of 1-6 mm 2 /s, a %Cp of 70 or greater and a %C A of no greater than 2, and a viscosity index improver which, when added to the lubricating base oil, results in an A/B ratio of less than 3.2 and a C/B ratio of less than 1.5. A is the thickening effect on the kinematic viscosity at 100°C, X is the kinematic viscosity at 100°C of a mixture of the lubricating base oil and 3 % by mass of the viscosity index improver, X 0 is the kinematic viscosity at 100°C of the lubricating base oil, B is the thickening effect on the HTHS viscosity at 150°C, Y is the HTHS viscosity at 150°C of a mixture of the lubricating base oil and 3 % by mass of the viscosity index improver, Y 0 is the HTHS viscosity at 150°C of the lubricating base oil, C is the thickening effect on the HTHS viscosity at 100°C, Z is the HTHS viscosity at 100°C of a mixture of the lubricating base oil and 3 % by mass of the viscosity index improver, and Z 0 is the HTHS viscosity at 100°C of the lubricating base oil. A = X - X 0 B = Y - Y 0 C = Z - Z 0 |
