Of course you do!
Well, if not, there's a reminder behind the cut.
Last night on my way home, I started reminiscing about this show, but wondered, "How did gas work in this scenario?
I came up with two possible scenarios. When he transforms, he is returned to the state he was in when the accident first happened. Which means, transform him, drain the tank, transform him back...unlimited fuel!
But that seems to have a problem due to the fact that it's creating something out of nothing. So, perhaps the food in his system is transformed into fuel. So, you feed him, transform him, drain the tank, transform him back, lather, rinse, repeat. Because a full stomach takes much less raw material to make a tank of gas, than it would corn for ethanol.
Hell, get a fleet of these guys, since it was a government project. Just make a deal with them and pay them very very well...