This invention relates to polymeric additives useful for inhibition of the deposit of paraffins and improvement of the flow properties of crude oils and to compositions containing crude oils and such additives. The polymeric additive according to the invention consists of a polymer formed by units derived from one or more alkyl esters of unsaturated monocarboxylic acids, one or more unsaturated alpha, beta-dicarboxylic compounds in the form of diacids, low alkyl diesters or anhydrides and one or more monomers having ethylenic unsaturation of the general formula CH.sub.2 .dbd.CZ.sub.1 Z.sub.2, in which Z.sub.1 and Z.sub.2 are the same or different and represent hydrogen, a halogen, a saturated, unsaturated or aromatic hydrocarbon group or an ester or ether group. Compounds containing a crude oil and 5 to 4000 ppm and preferably 100 to 1500 ppm of the additive have much improved flow properties.