The invention relates to a fuel for gasoline engines and diesel engines, containing small amounts of an ester of a mono- and/or poly-carboxylic acid with an alkyl alkanolamine or alkyl aminopolyalkylene glycol of the general formula (I): (I) in which R1 is a C6-C30-alkyl radical, R2 is a C6-C30 -alkyl radical or a hydroxyalkyl radical of the general formula (II): (II) and R3 is a hydroxylalkyl radical of formula (II), in which R4 is hydrogen or a C1-C6-alkyl radical and m is an integer from 0 to 100.