Thought you were supposed to reduce weight to improve gas mileage. Now we are adding iron to the gas tank?
since recieving energy from metal for running a car would be totally different than using gasline, weight might not be such an issue here. imo, that heat would be used to generate electricity sorta like a nuke reactor. with no engine as we know it and no or few batteries, this thing could weigh plenty and still be withing the parameters of functionality.