The present invention relates to a system and method for providing fuel to internal combustion engines including fuel activation prior to injection. The method carried out by the system comprises dissolving a mixture of gasses providing improved fuel dispersing after fuel injection into a combustion chamber. Dissolved gasses desorption is stimulated from a unsaturated fuel solution. Full control of fuel flows with dissolved gas/gasses to and from injectors and FET technology is based on Henry's law (dissolving gasses in the liquids) and Kelvin principle (vapor pressure over droplet surface). The system provides fuel to internal combustion engines and consists of compact components, including exhaust gasses recirculation system which can be easily added to existing diesel and gasoline engine fuel supply systems. The method and system were tested with 4 different types of engines. The new method can use any type of liquid fuel--petroleum or synthesized, and provides fuel economy in 12-20% decrease of emissions and up to 25% at variable engine loads and significantly at engine cold start.