| abstract |
(57) [Summary]nAn additive comprising an oil, a poly-alpha-olefin polymer dispersant having a number average molecular weight of greater than 2500, and sufficient metal dihydrocarbyl dithiophosphate to produce a phosphorus content of up to 0.1% by weight based on the total weight of the oil A lubricating oil composition comprising a combination. The poly-α-olefin polymer may be an ethylene α-olefin copolymer, for example, 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. |