Pretty sure there have been prototype engines that you use water and they run. Supposedly they've been suppressed... hard to believe anyone would do that!;-)
I'm skeptical of those stories of prototype ground breaking engines that are suppressed and bought out by oil companies or whatever. Sound like conspiracy theories or urban legends.
To me the fact that my wife's VW midsized SUV get 41 mpg is amazing enough. That's a long ways on one gallon of gasoline!
