Does water injection system improve fuel efficiency?

I’m trying to get better gas mileage in my 99 F 150. I’ve seen those ads for water injection systems in magazines and on the internet. Do those things actually work?”

No, they only work to take your money and can actually harm your engine in the long run. Water injection is a real process in piston engines, BUT only in VERY specialized cases. The later model P 51 Mustang fighter planes in WW II had water injection for short term emergency use. You want as much power as possible when people are shooting 20 mm cannons at you. The water helped cool down the supercharged engines and let them put out more horsepower. But putting a water injection system on a modern car or truck is not a good idea. Modern vehicles, when they are running correctly and have no problems, burn 99 percent of the fuel efficiently. So you really only have the ability to inprove combustion by a measely one percent. And that isn’t much of an improvement (plus it would be nearly impossible to squeeze that last one percent out anyway.) In September 2005 Popular Mechanics tested a water injection system out, and discovered the vehicle they put it in actually got twenty percent worse gas mileage. SO, leave that nonsence alone. The only way to get better gas mileage is to raise the gear ratio in the transmission (so the engine spins slower at a given speed and uses less gas) or lighten the vehicle’s overall weight so the engine has less to pull around. And of course you can make a vehicle a hybrid design, using electrical motors and regenerating brake systems. But changing a vehicle you already have into a hybrid would be an immense task, you’ be better off just buying an already made hybrid.