Water as fuel

No. Water is the waste product of combustion. It is ash. All this guy does is use electrolysis to split hydrogen and oxygen (reversing the conbustion process) and then he burns it. I can assure you that he's taking more power out of the wall socket his machine is plugged into than he gets back by burning the hydrogen and oxygen. There isn't anything new or especially useful here.

 

I didn't hear that claim anywhere in the video, but if that is what he claims, he's going to need one reaaaaaally big battery!

Yes, now you're into the realm of perpetual motion hoaxes, if that's what this guy's about. There is one line about him being able to run his car on water alone (though he isn't doing it right now - perhaps becuause he can't figure out that pesky perpetual motion thing, but I don't want to assume that), but it doesn't go into any detail about that. He does explicitly state that his welding torch machine is plugged-into a wall outlet.