A composition suitable for use as a lubricant or lubricant additive, which composition comprises the reaction product of (1) an .alpha.,.beta.-unsaturated dicarboxylic compound and (2) an olefinically unsaturated compound, wherein the .alpha.,.beta.-unsaturated dicarboxylic compound is comprised of at least one ester selected from the group consisting of fumaric esters and maleic esters, wherein the esterifying component comprises a monoalcohol having from 4 to 20 carbon atoms;
- the olefinically unsaturated compound comprises a monoolefinically unsaturated compound having from 12 to 24 carbon atoms;
- and the composition comprises at least about 30% by weight of (3) an intermediate molecular weight reaction product of (1) and (2), which intermediate molecular weight reaction product is neither the lower molecular weight ene reaction product nor the higher molecular weight polymerization product of (1) and (2).