Here is another technology that I have have followed for a while that you might find interesting. I actually saw these engines about 20 years ago on display here. There was a company in Utah making them, but they had a number of threats made against them and they has found explosive devices on their trucks. So I doubt that they are in business still. But this is proof they worked. If they were a hoax then the threats would not have been required to keep them off the market.
The plasma engines were originally designed for prop airplanes since they lacked a carburetor so they would not be limited by altitude. As a demonstration they modified a Pinto engine and ran the car for 60,000 miles on one gas charge. It costs about $100 to recharge the gases and the engines put out more energy than they intake:
http://www.infinite-energy.com/iemagazine/issue51/papp.html
http://www.rexresearch.com/papp/1papp.htm