Abstract: A stable and homogeneous fuel composition for an internal combustion engine comprising gasoline, an alcohol selected from the group consisting of methanol and ethanol, and water is provided. The composition is prepared by a process which comprises the steps of applying a high-frequency electric current of 500 kHz to 50 MHz to water, mixing said water with an alcohol selected from the group consisting of methanol and ethanol to obtain a mixture, applying a high-frequency electric current of 500 kHz to 50 MHz to said mixture, admixing said mixture with gasoline to obtain an admixture, and applying a high-frequency electric current of 500 kHz to 50 MHz to said admixture, or a process which comprises the steps of applying a high-frequency electric current of 500 kHz to 50 MHz to a mixture of water and an alcohol selected from the group consisting of methanol and ethanol, mixing gasoline with said mixture, and applying a high-frequency electric current of 500 kHz to 50 MHz to the resultant mixture.