The use of a reaction product comprising a quaternized nitrogen compound or of a fraction thereof which comprises a quaternized nitrogen compound and is obtained from the reaction product by purification, as a fuel additive in a proportion of from 10 to 5000 ppm by weight, based on the total amount of the fuel, where the reaction product has been obtained by a) reacting a quaternizable nitrogen compound comprising at least one quaternizable amino group with a quaternizing agent which converts the at least one quaternizable amino group to a quaternary ammonium group, where the quaternizing agent is the methyl or ethyl ester of an aliphatic, cycloaromatic or cycloaliphatic polycarboxylic acid; and b) transesterifying the remaining ester group of the quartenization product from stage a); where the transesterification is effected by means of an alcohol selected from a) polyalkoxylates of the general formula 1 in which: R 1 and R 5 are each independently H, alkyl, alkenyl or aryl, where at least one of the two radicals is H; R 2 , R 3 and R 4 are each independently H, C 1 -C 30 -alkyl, especially C 1 -C 5 alkyl; and n, m and o are each independently integer values from 0 to 100; having molecular masses from 40 to 10 000 g/mol, found by determining the OH number (DIN 53240-2); b) polyol-started polyalkoxylates having molecular masses in the range from 100 to 10 000 g/mol, found by determining the OH number (DIN 53240-2); where the compound a) or b) used for transesterification of the remaining ester group has a coefficient of partition logP of greater than 0.7, especially greater than 0.8, greater than 0.9, greater than 1, or greater than 1.1, where the logP value up to a value of about 6 is determined according to OECD Guideline 117 at 25°C in n-octanol/water, and above a value of 6 by the ACD/LogP method. a) reacting a quaternizable nitrogen compound comprising at least one quaternizable amino group with a quaternizing agent which converts the at least one quaternizable amino group to a quaternary ammonium group, where the quaternizing agent is the methyl or ethyl ester of an aliphatic, cycloaromatic or cycloaliphatic polycarboxylic acid; and b) transesterifying the remaining ester group of the quartenization product from stage a); a) polyalkoxylates of the general formula 1 in which: R 1 and R 5 are each independently H, alkyl, alkenyl or aryl, where at least one of the two radicals is H; R 2 , R 3 and R 4 are each independently H, C 1 -C 30 -alkyl, especially C 1 -C 5 alkyl; and n, m and o are each independently integer values from 0 to 100; having molecular masses from 40 to 10 000 g/mol, found by determining the OH number (DIN 53240-2); R 1 and R 5 are each independently H, alkyl, alkenyl or aryl, where at least one of the two radicals is H; R 2 , R 3 and R 4 are each independently H, C 1 -C 30 -alkyl, especially C 1 -C 5 alkyl; and n, m and o are each independently integer values from 0 to 100; having molecular masses from 40 to 10 000 g/mol, found by determining the OH number (DIN 53240-2); b) polyol-started polyalkoxylates having molecular masses in the range from 100 to 10 000 g/mol, found by determining the OH number (DIN 53240-2); <EOS>