摘要 |
<p>A lubricating oil composition comprising oil, and an additive combination comprising a poly alpha-olefin polymer dispersant with a number average molecular weight above 2500, and a metal dihydrocarbyl dithiophosphate sufficient to yield a phosphorous content of up to 0.1 percent weight based on the total weight of the oil. The poly alpha-olefin polymer can be ethylene alpha-olefin copolymer such as ethylene-1-butene or ethylene-1-butene-hydrocarbyl polyamine. Preferably, the ethylene-1-butene-hydrocarbyl polyamine has a number average molecular weight of about 3300.</p> |