Engine oil \s and methods for use in soot-producing engines. The engine oil contains a major amount of a base oil and a dispersant reaction product of A) a hydrocarbyl-dicarboxylic acid or anhydride, and B) at least one polyamine, that is post-treated with C) an aromatic carboxylic acid, an aromatic polycarboxylic acid, or an aromatic anhydride, wherein all carboxylic acid or anhydride groups of C) are attached directly to an aromatic ring. A molar ratio of carboxyl groups from components A) and C) to nitrogen atoms from component B) of from 0.9 to 1.3 is used to make the dispersant which also has a molar ratio of component C) to component B) of at least 0.4 and when component B) has an average of 4-6 nitrogen atoms per molecule, a molar ratio of A) to B) is from 1.0 to 1.6.