A method of preparing a lubricating oil additive composition comprising reacting (A) a nitrogen-containing reactant derived from reacting a first reaction product with a triglyceride, wherein the first reaction product is derived by reacting an alkanolamine and a base, wherein the nitrogen-containing reactant comprises three equivalents of a nitrogen-containing compound and one equivalent of glycerol, and wherein the nitrogen-containing reactant contains less than 10 mass percent of glycerol alkyl ester; (B) a source of boron; and (C) glycerol.