Abstract: Fuel activation apparatus for use in the pretreatment of fuel that is to be mixed with air for burning in combustion engines and the like. Fuel within a dielectric carrier is subjected through use of a field coil or other means to pulsed energy from an oscillator or other source at a frequency in a range corresponding to resonant frequencies for the molecular components of the fuel, the constituent elements of the fuel or protons of such elements. For fuels having a hydrogen constituent, operation in a frequency range of 16 to 42 Mega Hertz is suggested. For fuels having other inclusions, the operating frequency range may be expanded to include the nuclear resonance frequency for such components.