Low viscosity, high abrasion resistance engine oil composition

摘要

An engine oil composition that has lower viscosity then the lowest viscosity grade specified by the current standard (SAE (Society of Automotive Engineers) viscosity classification) and achieves excellent abrasion resistance under conditions of high temperature and high shear rate without an increase in the amount of anti-abrasion agent, said engine oil composition characterized by the following facts: the engine oil composition contains 0.02-0.12 mass % of zinc dithiophosphate, measured in the phosphorous amount based on the total weight of the composition, in a base oil compromised of a mineral oil and/or a synthetic oil; (1) the high-temperature high-shear viscosity at 150° C. and at a shear rate of 1x10⁶ s^-1 is less than 2.6 mPa.s; (2) the engine oil composition satisfies the following equation: $\frac{\mathrm{kinematic}\mathrm{viscosity}\mathrm{at}{100}^{\circ }C.\left({\mathrm{mm}}^2\text{/}s\right)}{\begin{array}{c}\mathrm{high}\text{-}\mathrm{temperature}\mathrm{high}\text{-}\mathrm{shear}\mathrm{viscosity}\mathrm{at}{100}^{\circ }C.\\ \mathrm{and}\mathrm{at}a\mathrm{shear}\mathrm{rate}\mathrm{of}1x{10}^6{s}^{-1}\left(\mathrm{mPa}.s\right)\end{array}}<=1.3.$