The present invention relates to a fuel oil additive comprising A) a copolymer of ethylene and from 18 to 35 mol % of at least one acrylic ester or vinyl ester having a C1-C18-alkyl radical and a degree of branching of less than 5 CH3/100 CH2 groups, and B) a comb polymer comprising structural units formed from B1) at least one olefin as monomer 1, which bears at least one C8-C18-alkyl radical on the olefinic double bond, and B2) at least one ethylenically unsaturated dicarboxylic acid as monomer 2, which bears at least one C8-C16-alkyl radical bonded via an ester group, in which the parameter Q Q = ∑ i   w 1  i · n 1  i + ∑ j   w 2  j · n 2  j in which w1 is the molar proportion of the individual chain lengths n1 in the alkyl radicals of monomer 1, w2 is the molar proportion of the individual chain lengths n2 in the alkyl radicals of the ester groups of monomer 2, n1 are the individual chain lengths in the alkyl radicals of monomer 1, n2 are the individual chain lengths in the alkyl radicals of the ester groups of monomer 2, i is the serial variable for the chain lengths in the alkyl radicals of monomer 1, and j is the serial variable for the chain lengths in the alkyl radicals of the ester groups of monomer 2 assumes values of from 23 to 27.