The invention concerns a multifunctional additive enabling fuels to be operable in cold conditions, consisting of copolymers of at least a dicarboxylic compound with at least an olefin, and whereon are grafted nitrogenous functions and/or esters of general formula (1) wherein: R1 and R2, and R4 and R5, R3 and R6 are hydrogen or alkyl radicals, and x is selected among the amine salts and N-alkylpolyalkylenepolyamines and their monohydroxylated and polyhydroxylated derivatives, N-alkylpolyalkylenepolyamine alkylesters and esters, and alkylamines and N-alkylpolyalkylenepolyamines.