A polysuccinimide composition is prepared by reacting a mixture of an alkenyl or alkylsuccinic acid derivative, an unsaturated acidic reagent copolymer, and a polyamine under reactive conditions. The alkenyl or alkyl substituent of the alkenyl or alkylsuccinic acid derivative has a Mn of from 140 to 3000. The unsaturated acidic reagent copolymer has an average degree of polymerization of from 2 to 20, and is a copolymer of an unsaturated acidic reagent and an olefin having a Mn of at least 1000. The polyamine has at least three nitrogen atoms and has from 4 to 20 carbon atoms.