Multifunctional additive for fuel oils

A process for the simultaneous improvement of the lubricating activity and cold flow properties of fuel oils having less than 500 ppm sulfur comprising adding to said fuel oils an additive comprising:

• a) 5-95% by weight of at least one oil-soluble amphiphile of the formulae
• in which R1 is an alkyl, alkenyl, hydroxyalkyl or aromatic radical having 5 to 50 carbon atoms, X is O or S, y is 1,2,3 or 4, R2is hydrogen or an alkyl radical having hydroxyl groups and having 2 to 10 carbon atoms wherein R1 and R2 together contain at least 15 carbon atoms and R3 is an alkyl radical carrying nitrogen and/or hydroxyl groups and having 2 to 10 carbon atoms or a C1-C20-alkyl radical, and b) 5 to 95% by weight of a terpolymer of ethylene, the vinyl ester of one or more aliphatic, linear or branched monocarboxylic acids which contain 20 to 20 carbon atoms in the molecule and a C5-C7-olefin, comprising from 9 to 18 mol% of vinyl ester and from 0.5 to 5 mol% of olefin (based in each case on the terpolymer) and having a melt viscosity, measured at 140° C., of from 20 to 10,000 mPas.