| abstract |
An engine oil composition having a base oil, an ashless dispersant, a metal-containing detergent, zinc dithiophosphate and a sulfur-containing phenol derivative. Examples of sulfur-containing phenol derivative include 2,4-bis{(octylthio)methyl}-o-cresol, 2,2-thiodiethylenebis{3-(3,5-di- t-butyl-4-hydroxyphenyl)propionate}, and tridecyl 2-(3,5-di-ti-butyl- 4-hydroxybenzylthio)acetate. |