I've done more reading and watched a couple more videos. Everybody knows the technology currently in use is terribly inefficient, and it would be fantastic to see something come along which would make a huge difference. In the following video and elsewhere, the claim is made that GEET can fuel an engine with water plasma (H-H-O). The caption reads, "Crude oil is only used to prime the engine. The primary fuel is water." It also states that atomic reactions are going on.

"the carbon doesn't vanish, it is transmuted into another element." (paraphrasing) ... of course, water contains no carbon. But, molecular changes do not transmute one element to another.
I want to believe someone will come up with something revolutionary. Promoters of perpetual motion machines have often made convincing demonstrations though, and this still smells like snake oil to me.
Plasma behaves differently than gas because it is electrically conductive and responds to magnetic fields -
wikipedia