Viscosity modifier polymers (E-98)

A lubricating oil composition comprising a major amount of lubricating oil and a viscosity modifying effective amount of viscosity modifier comprising (i) copolymer of ethylene and at least one other alpha-olefin monomer, wherein said compolymer has a molecular weight distribution characterized by at least one of a ratio of M.sub.w /M.sub.n of less than 2 and a ratio of M.sub.z /M.sub.w of leas than 1.8, and wherein said compolymer comprises intramolecularly heterogeneous polymeric chains containing at least one crystallizable segment of methylene units and at least one low crystallinity ethylene-alpha-olefin copolymer segment, wherein said at least one crystallizable segment comprises at least about 10 weight percent of said copolymer chain and contains an average ethylene content of at least about 57 weight percent, and wherein said low crystallinity segment contains an average ethylene content of from about 20 to 53 weight percent, and wherein at least two portions of an individual intramolecularly heterogeneous chain, each portion comprising at least 5 weight percent of said chain, differ in composition from one another by at least 7 weight percent ethylene, and (ii) at least one other viscosity modifier different from said copolymer (i).