| abstract |
A lubricating oil formulation is described which is useful in internal combustion engines. More particularly, lubricating oil compositions for internal combustion engines are described with comprise (A) at least about 60% by weight of oil of lubricating viscos-ity, (B) at least about 2.0% by weight of at least one carboxylic derivative composition produced by reacting (B-1) at least one substituted succinic acylating agent with (B-2) from about 0.70 equivalent up to less than one equivalent, per equivalent of acylating agent, of at least one amine compound characterized by the presence within its structure of at least one HN< group, and wherein said substituted succinic acylating agent con-sists of substituent groups and succinic groups wherein the substituent groups are derived from a polyalkene, said polyalkene being characterized by an Mn value of about 1300 to about 5000 and an Mw/Mn value of about 1.5 to about 4.5, said acylating agents being characterized by the presence within their structure of an average of at least 1.3 succinic groups for each equivalent weight of substituent groups, and (C) from about 0.01 to about 2% by weight of at least one basic alkali metal salt of sulfonic or carboxylic acid. The oil compositions of the invention also may contain (D) at least one metal dihydrocarbyl dithiophosphate and/or (E) at least one carboxylic ester derivative composition, and/or (F) at least one partial fatty acid ester of a polyhydric alco-hol, and/or (G) at least one neutral or basic alkaline earth metal salt of at least one acidic organic com-pound. In one embodiment, the oil compositions of the present invention contain the above additives and other additives described in this specification in amounts sufficient to enable the oil to meet all the performance requirements of the new API Service Classification ident-ified as SG. |