Patent ID: 8758456

Claim:
A diesel fuel for fuel injection comprising: a major amount of middle distillate fuel having a sulfur content of 50 ppm by weight or less; and a reaction product of (a) a hydrocarbyl substituted dicarboxylic acid, anhydride, or ester, wherein the hydrocarbyl group of the hydrocarbyl dicarboxylic acid, anhydride, or ester comprises a polyisobutylene radical and (b) an amine compound or salt thereof of the formula wherein R is selected from the group consisting of hydrogen and a hydrocarbyl group containing from about 1 to about 15 carbon atoms, and R 1 is selected from the group consisting of hydrogen and a hydrocarbyl group containing from about 1 to about 20 carbon atoms, wherein the reaction product is made under conditions sufficient to provide that the reaction product contains less than one equivalent of an amino triazole group per molecule of reaction product, and wherein the reaction product is present in an amount ranging from about 30 mg to about 150 mg per Kg of fuel, which amount is sufficient to improve the performance of diesel direct and/or indirect fuel injectors, wherein the reaction product is characterized by an FTIR spectrum having a peak intensity in a region of from about 1630 cm −1 to about 1645 cm −1 that ranges from about 5 to about 45% of peak intensities of other peaks in a region of from about 1500 cm −1 to about 1800 cm −1 .