Synergistic dispersants

An engine oil composition comprising:

• about 50% to about 99% by weight of a base oil, based on the total weight of the engine oil composition, and an additive composition, said additive composition comprising:
• (a) at least 0.05 percent by weight, based on a total weight of the engine oil composition, of a first dispersant that is a reaction product of A) a hydrocarbyl-dicarboxylic acid or anhydride, and B) at least one polyamine wherein said reaction product is post-treated with a non-aromatic dicarboxylic acid or anhydride having a number average molecular weight of less than about 500;
• and
• (b) at least 0.05 percent by weight, based on a total weight of the engine oil composition, of a second dispersant that is a reaction product of A′) a hydrocarbyl-dicarboxylic acid or anhydride, and B′) at least one polyamine, and wherein said reaction product is post-treated with C) an aromatic carboxylic acid, an aromatic polycarboxylic acid, or an aromatic anhydride wherein all carboxylic acid or anhydride groups are attached directly to an aromatic ring, wherein the reaction product of the second dispersant has a ratio of A′ to B′ in the range of 4:3 to 2:1.