Abstract: Internal combustion engines generally suffer from inadequate time to completely combust all the fuel in a given cycle. Therefore, any method for increasing the rate and completion of combustion is welcomed. A large excess of electrons are admitted to the combustion zone attached to a fine water droplet spray. The charged spray enters through the air intake valves at the beginning of the intake stroke. The charged spray becomes well mixed with the charge of air prior to fuel injection and the well mixed electrons provide for catalytic action. Electron catalyzed combustion reactions occur faster and at lower temperatures. The lower temperature reduces NOx and the faster burning increases efficiency and reduces soot formation. The catalytic benefits of charged water fumigation is only observed once the electron concentration exceeds a threshold value.