Industrial fuels comprised of mixtures of asphaltenic heavy hydrocarbon fractions and light fractions are provided wherein the flocculation of asphaltenes is minimized by the addition of from 50 to 5000 ppm of an additive composed of a constituent A and/or a constituent B to render the composition homogeneous and stable. Constituent A results from the condensation of a linear N-alkyl polyamine with a cyclic anhydride and constituents B results from the reaction of an ethoxylated amine with a carboxylic acid of C.sub.8 to C.sub.30.