Abstract: An automatic fuel saver for a vehicle engine comprises a cyclonic turbulence chamber for connection between the engine intake manifold and the carburetor that supplies a fuel-air stream to the manifold. An air scoop is positioned at the front of the vehicle to collect supplemental air due to the forward motion of the vehicle. The supplemental air is conducted by a conduit to the turbulence chamber where it is introduced tangentially into the chamber and mixes cyclonically with the fuel-air stream being drawn into the engine from the carburetor, thereby providing supplemental oxygen to the engine in an amount which varies directly with the forward speed of the vehicle and the engine power demand.