abstract |
A lubricant composition with improved stability to oxidation, especially of silver parts of diesel engines, comprises a major amount of a base oil; and a minor amount of a synergistic additive composition comprising: (i) a triazole compound substituted with an aryl moiety, with the proviso that the triazole compound is not an alkyl bis-3-amino-1,2,4-triazole; and (ii) a nitrogen-containing compound represented by the formula R<1>-NH-R<2>, wherein R<1> and R<2> are each selected from at least one aryl moiety comprising from about 6 to about 30 carbon atoms, hydrogen, halogen, hydroxy, hydrocarbyl, substituted hydrocarbyl, amino, amido, phosphoro, and sulfono. |