I have a 2004 f 250 superduty v10 my wife owns a 2008 g5 gt but would rather use the truck fells much safer my question is what is the best gas miliage that you can possible get Ive been doing some reading on water 4 gas any body else see this Andre

 

I once hit 19mpg, on the interstate riding about 58mph.

Using anything that doesn't burn as hot as gasoline will result in poorer mileage and less power unless you do a lot of supporting mods. I've heard people say they have had good results with hydrogen dioxide boosting systems. However, I am not ready to dump to water into my engine plus the system calls for a decent amount of power from the electrical system to separate the hydrogen from the oxygen, I am not buying into it yet.