An oil-soluble lubricating oil additive composition prepared by the process which comprises reacting (A) reacting a copolymer of an (i) an unsaturated acidic reagent; and (ii) a mono-olefin, with at least one linking hydrocarbyl di-primary amine, thereby producing a hybrid succinic anhydride copolymer having from about 10% to about 90% unreacted anhydride groups; and subsequently (B) reacting the hybrid succinic anhydride copolymer with a second amine compound, thereby producing the succinimide; and (C) reacting the succinimide with at least one post-treating agent selected from a cyclic carbonate, a linear mono-carbonate, a linear poly-carbonate, an aromatic polycarboxylic acid, an aromatic polycarboxylic anhydride, an aromatic polycarboxylic acid ester, or mixtures thereof.