Abstract: A process is disclosed which comprises reacting at elevated temperature(a) a copolymer of an olefin and a monomer having the structure ##STR1## wherein X and X.sup.1 are the same or different provided that at least one of X and X.sup.1 is such that the copolymer can function as a carboxylic acylating agent and(b) a succinimide prepared from an acyclic hydrocarbyl substituted succinic acylating agent and a polyamine wherein the hydrocarbyl substituted succinic acylating agent is prepared by reacting a polyolefin and an acylating agent of formula I under conditions such that at least 75 mole % of the starting polyolefin is converted to the hydrocarbyl-substituted succinic acylating agent. Hydrocarbyl substituted succinic acylating agents derived from high reactivity PIB's are preferred.