Abstract: A fuel saving and pollution emission reduction system (10) that utilizes an air ionizer (58) that is easily attached inline between a vehicle air-intake hose (106) and a fuel injection throttle body (108) or a carburetor air-intake structure (110). The air ionizer, which functions with either gasoline or diesel fuel engines is operated by an electronic ionizer control unit (12). The unit (12) is located within the confines of the vehicle's engine compartment and is operated by a 12-volt d-c power source (104) derived from the vehicle's battery (102). When air from the vehicle air-intake hose (106) Passes through the air ionizer (12) the air is ionized and is mixed with the non-ionized air to produce an oxygen-enriched fuel-air mixture. The oxygen-enriched mixture allows a fuel saving and produces a cleaner burning fuel which reduces hydro-carbon exhaust emission levels.