Abstract: A middle distillate fuel additive comprising the reaction product resulting from the combining of a hydrocarbyl succinic anhydride and a hydroxyamine. The lubricating properties of low sulfur-content middle distillate fuels, such as diesel, jet or bio-diesel fuels, can be significantly improved by inclusion therein of such additive compounds. The use of these middle distillate fuel additives makes it possible to avoid mechanical failure problems, such as fuel pump or injector failure, otherwise caused by inadequate fuel lubricity, while still retaining the environmental benefits of using a low sulfur fuel.