Condensation products made by reacting an .alpha.-hydroxyalkyl hydroxy-aromatic compound also having at least one non-fused hydrocarbyl substituent with at least one olefinic nitrile, carboxylic acid or carboxylic acid derivative are useful as additives for fuels and lubricants. The total number of carbon atoms in the non-fused hydrocarbyl substituents is at least about 7 while the .alpha.hydroxyalkyl group contains from 1 to about 36 carbons and the olefinic acid or nitrile reactant usually contains 2 to about 40 carbon atoms. Products made from hydroxymethyl alkyl-substituted phenols and .alpha.,.beta.-olefinic acid derivatives such as maleic anhydride and particularly useful. Similarly useful post-treated products can be made from these condensation products by further reaction with alcohols, amines, metal salts or metals.