Abstract: A vacuum responsive injection system for engines which includes a vacuum conduit extending from a carburetor to a crankcase ventilation valve, injection means in said vacuum conduit connected to a metering means through a tube, the metering means is operatively attached to a liquid containing reservoir having an alcohol water mixture, the metering means includes an air bleed which allows the ratio of liquid to air to be finely varied so that upon demand by the engine through the vacuum, the fluid formed from alcohol, water and air mist can be introduced within the engine for increased mileage, less oil consumption, and removal of carbon.