To provide a lubricating oil composition for internal combustion engines suitable as a diesel engine oil composition which has a low ash content, which has reduced effects on a particulate trap and an oxidation catalyst and which has enough oxidation stabilizing properties and anti-coking properties.
A lubricating oil composition is obtained by blending (A) 0.08 wt.% or more in terms of the nitrogen content in the composition of an ashless dispersant, (B) 0.5 wt.% or more of a phenol-based ashless antioxidant, (C) a metal-based cleaning agent in an amount to give a calcium content of 0.08-0.14 wt.% in the composition and (D) 0.7 wt.% or less of a sulfuric acid ash content based on the total weight of the composition, with a lubricating oil base oil.
TAKESHIMA SHIGEKI
SASAKI YOSHIKI
MITSUBISHI MOTORS CORP