Abstract: The invention relates to an aqueous fuel composition having a homogeneous liquid phase, a so called microemulsion, containing a liquid hydrocarbon fraction, ethanol and an additive with an emulsifying and solubilizing ability. The composition contains a) 70-95% by weight of an hydrocarbon fraction having a boiling point within the range from 130 to 425° C., b) 2-25% by weight of ethanol, c) 0.002-0.8% by weight of water, and d) 0.2-25% by weight of an additive comprising 5-100% by weight of an nitrogen-containing surractant, such as an amine surfactant, an ether amine surfactant, an amine oxide surfactant and an amido surfactant, and optionally an alcohol having a hydrocarbon group of 5-24 carbon atoms. Preferably the additive contains 5-90% by weight of the nitrogen-containing surfactant and 10-95% by weight of the alcohol. The composition, which can be stored for long periods. may be used as a fuel in diesel engines.