Abstract: The invention relates to comb polymers based on olefin copolymer macromonomers. Preferred comb polymers are copolymers of optionally hydrogenated olefin copolymer macromonomers of formula I ##STR1## wherein R' is hydrogen or methylR.sub.1 is the organic residue of a lithium-organic compound,[A] is a segment formed by 1,4-addition of butadiene potentially substituted with a C1-C6 alkyl residue[A'] is a segment formed by vinyl addition of butadiene potentially substituted with a C1-C6 alkyl residueand n+m stands for an integer of from 7 to 3,000, with (meth)acrylic ester monomers of formula II ##STR2## wherein R' is hydrogen or methyl, andR.sub.2 is an alkyl residue with 1 to 26 carbon atoms.

Abstract: Crankcase lubricant compositions for use in automobile or truck engines comprise a major amount of a lubricating oil, added copper present in oil-soluble form and an oil-soluble diamine sulphide. The specified additives provide a highly effective antioxidant system, which may be used, for example, in lubricating oils which are substantially free of phosphorus.