ENGINE OIL COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain an engine oil composition that has extremely excellent cleanliness. SOLUTION: The objective engine oil composition is obtained characteristically by formulating 0.5-20 mass %, in total, of (A) boron-containing succinimide and (B) boron-free succinimide where the weight ratio of the component A/the component B is 1.0-3.5 and (C) 0.01-0.5 mass % of an alkaline earth metal cleaning agent calculated as alkaline earth metal element and (D) 0.03-0.20 mass % of zinc dithiophosphate calculated as phosphorus element, to a lubricant base oil.