| abstract |
To provide a lubricating oil composition in which zinc dithiophosphate is stably dissolved or dispersed in a lubricating oil. Based on the total mass of the composition, (A) 1.5 to 4.0% by weight of one or more zinc dithiophosphates represented by the following formula (1) in terms of Zn, (B) 0.2 to 0.8% by weight of calcium sulfonate in terms of Ca, (C) A lubricating oil composition containing 0.15 to 0.4% by weight of barium sulfonate in terms of Ba, and (D) a base oil. (In the formula, R 1 , R 2 , R 3 and R 4 may be the same or different and each independently represents a primary or secondary alkyl group having 3 to 12 carbon atoms, or 6 carbon atoms. Represents an aryl group of ˜12.) [Selection figure] None |