Alkenyl or alkyl succinimide additives which are the reaction product of a high molecular weight alkenyl- or alkyl-substituted succinic anhydride and a polyalkylene polyamine having an average of greater than 4 nitrogen atoms per mole, wherein the reaction product is post-treated with a cyclic carbonate, are compatible with fluorocarbon engine seals, and, for concentration levels at which fluorocarbon seal compatibility is achieved, possess improved dispersancy and/or detergency properties when employed in lubricating oils and fuels.