Abstract: Oil-soluble combinations of (A) ethylene polymer or copolymer, (B) normal paraffinic wax composed of normal hydrocarbons whose average molecular weight is within the range of from 300 to 650, and (C) nitrogen compounds, such as amides, amine salts and ammonium salts, of carboxylic acids or anhydrides, are useful in improving the cold flow properties of distillate hydrocarbon fuel oils. Preferably, the wax contains n-paraffins ranging from C.sub.23 to C.sub.37 inclusive. If desired, the combination can be usefully stabilized by the addition of one or more compatibility additives, i.e. a polymer having alkyl side chains of 6 to 30 carbon atoms and derived from carboxylic acid esters and/or olefins or C.sub.8 -C.sub.18 alkanol, e.g. tridecyl alcohol or mixtures of said polymer and alkanol.

Abstract: The combination of an oil-soluble borated acylated nitrogen compound (e.g., borated polybutenylsuccinic anhydride reacted with polyamine) and solvent oil is usefully added to gasoline fuel for combustion in a spark ignition internal combustion engine exhibiting dieseling (also known as after-run or run-on) whereby said combustion results in alleviation of said dieseling.