Abstract: Novel compositions, useful as additives for normally liquid fuels to impart dispersancy, anti-icing and rust inhibiting properties thereto, comprise salts of amines prepared by the Mannich reaction between a hydroxy-substituted aromatic compound, usually an alkylphenol in which the alkyl group contains at least about six carbon atoms; formaldehyde or a reversible polymer thereof; and a hydroxyalkyl-substituted amine such as diethanolamine. The acid portion of the salt is preferably derived from a carboxylic acid containing about 14-24 carbon atoms especially an aliphatic radical-substituted succinic acid or an acidic ester thereof. Epoxide adducts of such salts are useful for the same purposes.

Abstract: Esters made from (A) high molecular weight carboxylic acid reagents derived from low molecular weight ethylenically unsaturated carboxylic acid reagents and oxidized ethylene-propylene interpolymers and (B) mono- or polyhydric alcohols are useful in lubricant compositions and normally liquid fuel compositions as viscosity improving agents and sludge dispersants. Esters wherein the low molecular weight reagent is maleic anhydride and the alcohol is a polyol such as pentaerythritol are particularly useful.

Abstract: Improved fuel compositions with decreased tendency to form deposits in the carburetor and on "early fuel evaporation" heating elements, inlet valves and the like contain a normally liquid fuel (usually a hydrocarbon fuel), a carboxylic acid ester which is either (1) an ester of a polyol and a C.sub.5 -C.sub.15 monocarboxylic acid or (2) an alkanol ester of a substituted succinic acid, and an oil-soluble, ester-type, nitrogen-free dispersant derived from a polyhydric alcohol and characterized by the presence therein of a substantially saturated aliphatic hydrocarbon-based radical having at least about 30 carbon atoms.

Abstract: Improved fuel compositions with decreased tendency to form deposits in the carburetor and on "early fuel evaporation" heating elements, inlet valves and the like contain a normally liquid fuel (usually a hydrocarbon fuel), a carboxylic acid ester of lubricating viscosity, and an oil-soluble nitrogen-containing dispersant. The dispersant is characterized by the presence therein of a substantially saturated hydrocarbon-based radical having at least about 50 carbon atoms, and it is preferably a carboxylic dispersant (e.g., the reaction product of a polyisobutenyl succinic acid-producing compound with a polyethylene polyamine) or a Mannich-type dispersant (e.g., the reaction product of an alkyl phenol with formaldehyde and a polyethylene polyamine).