ENGINE OIL COMPOSITION FOR CONTAINING EXTREME-PRESSURE ADDITIVE, WHICH HAS EXCELLENT EXTREME PRESSURE

摘要

PURPOSE: Provided is an engine oil composition to contain zincdialkyldithiophosphate and calciumsalicylate as an extreme-pressure additive, which has an excellent extreme pressure, increases oxidative stability without changing abrasion resistance, and reduces a poisoning of catalysts. CONSTITUTION: The engine oil composition comprises a lubricant as a base oil, and zincdialkyldithiophosphate and calciumsalicylate as an extreme-pressure additive. The extreme-pressure additive consists of zincdialkyldithiophosphate represented by the formula 1(400-800 ppm based on Zn content) and calciumsalicylate represented by the formula 2 or formula 3(1000-1300 ppm based on Ca content). In the formula 1, R1, R2, R3 and R4 are C1-C20 alkyl groups. In the formula 2 or 3, R1 is a C1-C14 alkyl group.