| abstract |
【Task】 As a lubricating oil for internal combustion engines, it is required to have a low friction property both when fresh and deteriorated, that is, to maintain fuel saving performance over a long period of time. It is required that the seal rubber is difficult to deteriorate. [Solution] In lubricating base oil, based on the total amount of the composition, (A) 0.04 to 0.10% by mass of zinc dialkyldithiophosphate in terms of phosphorus concentration, (B) 0.05 to 4.0% by mass of phenyl-α-naphthylamine, (C) Molybdenum dithiocarbamate friction reducer 0.02 to 0.15% by mass in terms of molybdenum, and (D) from the group consisting of thiazole compound, thiadiazole compound, dithiocarbamate compound, dihydrocarbyl polysulfide compound, sulfurized ester compound 0.01 to 0.5% by mass of one or more selected sulfur-containing compounds selected in terms of sulfur concentration, To obtain a lubricating oil composition for an internal combustion engine. [Selection figure] None |