NOVELTY - A water blended fuel composition is obtained by combining hydrocarbon fuel, water and nitrogen-free surfactant (C). The hydrocarbon fuel is liquid at normal temperature. Component (C) comprises (a) nitrogen-free surfactant of hydrocarbyl substituted carboxylic acid, or a reaction product or reactive equivalent of hydrocarbyl substituted carboxylic acid with an alcohol, and (b) nitrogen-free surfactant (I-VI). The hydrocarbyl substituent of acid or reactive equivalent contains at least 30 carbon atoms.    USE - Used in open-flame burner (domestic, commercial and industrial burner, oil fired combustion unit, oil fired power plant, rotary kiln incinerator, liquid injection kiln, fluidized bed kiln, cement kiln, steel and aluminum forging furnace, fired heater and boiler used in schools, hospitals, apartments and ships including deep draft vessels) and internal combustion engine such as gasoline or diesel internal combustion engine including automobile and truck engines, two-cycle engines, aviation piston engine and marine and rail diesel engine.    ADVANTAGE - The water blended fuel composition has high combustion efficiency with reduced emission of nitrogen oxides.    DETAILED DESCRIPTION - A water blended fuel composition is obtained by combining hydrocarbon fuel, water and nitrogen-free surfactant (C). The hydrocarbon fuel is liquid at normal temperature. Component (C) comprises (a) nitrogen-free surfactant of hydrocarbyl substituted carboxylic acid, or a reaction product or reactive equivalent of hydrocarbyl substituted carboxylic acid with an alcohol, and (b) nitrogen-free surfactant of at least one compound of formula: RO(R'O)nR"'(I), RO(R"H(OR)-R'O)nR"' (II), RCOO(R'O)nR"' (III), RCOO(R"H(OR)-R'O)nR"' (IV), R(OR')xOR-C(O(R'O)yR)H-R"(R'O)xR (VI) or of formula (5). The hydrocarbyl substituent of acid or reactive equivalent contains at least 30 carbon atoms.    R=H or 60C hydrocarbyl group;    R',R"=1-20C alkylene group;    R"'=H, acyl or 30C hydrocarbyl;    n,x-z=0-50; and    x+y+z=1.    INDEPENDENT CLAIMS are included for the following:    (1) combustion process, which involves combusting the water blended fuel composition in equipment such as open flame burner and/or engine; and    (2) method for preparing water blended fuel composition, which involves mixing hydrocarbon fuel, water and nitrogen-free surfactant at a shear rate of up to 500000/second.