Abstract: A novel system for introducing a combustible liquid fuel into a gasoline combustion engine to obtain substantially perfect combustion and thereby prevent pollution, which system comprises heating means for elevating the temperature of the liquid gasoline fuel above its critical temperature, thereby converting it to its gaseous state; pressure means for providing a positive pressure as the liquid fuel is transported to the heating means; and means for discharging and rapidly expanding the gaseous fuel into the mixing chamber of the engine where it is admixed with air to provide a combustible mixture for burning and operation of the engine, the pressure means providing a pressure sufficient to maintain the fuel in its gaseous state immediately after it is discharged from the heating means into the mixing chamber.