Abstract: Disclosed is an in situ or "one pot" process for making a fuel additive comprising reacting an excess of at least one N-primary alkylalkylene diamine with maleic anhydride in the presence of from 20 to 36 weight percent of a mineral oil reaction diluent at a temperature ranging from ambient to about 225.degree. F. and recovering a product containing a primary aliphatic hydrocarbon amino alkylene substituted asparagine, an N-primary alkylalkylene diamine in the reaction oil with the product having a by-product succinimide content not in excess of 1.0 weight percent, based on the weight of asparagine present.