NOVELTY - An alcohol based fuel and/or biofuel composition contains dimethoxymethane (A), propylene glycol monoalkyl ether and/or butylene glycol monoalkyl ether (B), and 1 or more 1-4C alcohol (C). Component (A) is totally or partially replaced with compound(s) capable of improving combustion speed, such as di-tert-butylperoxide, ethyl nitrate, triethylene glycol dinitrate and meta-nitro benzoctadecylamide.    USE - As substitute of burning oils, gasoline and diesel used in internal combustion engine.    ADVANTAGE - The alcohol based fuel and/or biofuel composition is economically mixed with diesel or gasoline using conventional engines, and reduces emission of fuel, carbon dioxide, propylene oxide and/or butylenes oxide. The composition improves combustion efficiency and flame propagation speed and thereby lowers ignition temperature of fuel, and maintains single-phase stability in mixture with hydrocarbon even if exposed to high ambient moisture, cold weather and water filtrations. The composition is efficiently used in engines at low temperature and low compression ratio, thereby allows the manufacture to use economic, lightweight and inexpensive material with improved weight-to-power ratio and lower capacity cooling system. Space for combustion of remaining fuel is reduced. The water-extinguishable composition reduces accident risk in vehicle catching fire by producing cold flame, and has high octane number, favorable corrosion resistance and lubricity (claimed).    DETAILED DESCRIPTION - An alcohol based fuel and/or biofuel composition contains dimethoxymethane (A), propylene glycol monoalkyl ether and/or butylene glycol monoalkyl ether (B), and 1 or more 1-4C alcohol (C). Component (A) is totally or partially replaced with compound(s) capable of improving combustion speed, such as di-tert-butylperoxide, ethyl nitrate, triethylene glycol dinitrate, meta-nitro benzoctadecylamide and other compounds, used for reducing cetane number in diesel. Component (B) is partially or totally replaced with compound(s) such as propoxyalcohol and/or butoxyalcohol in which alcohol contains 1-4 carbon atoms, polyoxypropylene glycol monoalkyl ether or polyoxybutylene glycol monoalkyl ether. The alcohol based fuel and/or biofuel composition is capable of used in internal combustion engine designed for gasoline or diesel, without requiring engine modification. The composition is in pure form or mixed with diesel, burning oil or gasoline in defined proportion according to the amount and kind of fuel to be replaced, and has efficiency similar to the composition with replaced fuel. The composition produces low amount of fuel emission and carbon dioxide than conventional fuels. The components of biofuel composition are obtained from vegetable matter or biomass, allowing to avoid the usage of petroleum based product. An INDEPENDENT CLAIM is included for formulation of alcohol based fuel and/or biofuel composition, which involves mixing components (A-C) in defined proportion, to form fuel composition. The biofuel composition has formulations (a-g) when used as minor component of additive or fuel and as major component of fuel in mixture with gasoline or with one or more individual components of gasoline in gasoline engine, and as minor component of additive or fuel and as major component of fuel in mixture with diesel or burning oil in internal combustion engine, respectively. Formulation (a) contains component (A) (in vol.%) (14-29), component (B) (5-20) and component (C) (81-51). Formulation (b) contains component (A) (12-35), component (B) (7-14) and component (C) (81-51). Formulation (c) contains component (A) (9-19), component (B) (10-30) and component (C) (51-81). Formulation (d) contains component (A) (43-83), component (B) (3-20) and component (C) (14-37). Formulation (e) contains component (A) (43-83), component (B) (5-14) and component (C) (12-43). Formulation (f) contains component (A) (43-83), component (B) (10-30) and component (C) (7-27). Formulation (g) contains component (A) (35-43), component (B) (6-22) and component (C) (43-51). The combined proportions of components (B,C) is 18 vol.%, 29 vol.%, 27 vol.% and 33 vol.%, when used as minor component of additive or fuel and as major component of fuel in mixture with gasoline or with one or more individual components of gasoline in gasoline engine, and as minor component of additive or fuel and as major component of fuel in mixture with diesel or burning oil in internal combustion engine, respectively. The proportion of component (B) is 10 vol.%, 14 vol.%, 10 vol.% and 14 vol.%, when used as minor component of additive or fuel and as major component of fuel in mixture with gasoline or with one or more individual components of gasoline in gasoline engine, and as minor component of additive or fuel and as major component of fuel in mixture with diesel or burning oil in internal combustion engine, respectively.