Thanks for reply thought I would add this part which goes to fuel burn reduction, from wikireadya: As a general rule, the fuel mixture is set at full rich on an aircraft engine when running it at a high power settings (such as during takeoff). The extra fuel does not burn; its only purpose is to evaporate to absorb heat. This uses up more fuel, and it also decreases the efficiency of the combustion process. By using water injection, the cooling effect of the water allows the fuel mixture to be run leaner at its best-power setting. Many military aircraft engines of the 1940s utilized a pressure carburetor, a type of fuel metering system similar to a throttle body injection system. In a water-injected engine, the pressure carburetor features a mechanical derichment valve which makes the system nearly automatic. When the pilot turns on the water injection pump, water pressure moves the derichment valve to restrict fuel flow to lean the mixture while at the same time mixing the water/methanol fluid in to the system. When the system runs out of fluid the derichment valve shuts and cuts off the water injection system, while enriching the fuel mixture to provide a cooling quench to prevent sudden detonation.
Due to the cooling effect of the water, aircraft engines can run at much higher manifold pressures without detonating, creating more power. This is the primary advantage of a water injection system when used on an aircraft engine.
