"little bit" is the operative phrase. I've had wonderful folks in the community teach me everything that I know.
I think it'll do a little better than the C&D testing down in Baja. There are quite a few areas where, yes, you're into the throttle a bit, but if you have the stones, you're over 100mph in a truck like a raptor or TRX, and crazy enough you get decent gas mileage.
The challenge is, other sections, it'll get 2 MPG. I have literally had my dash telling me that I'm 50 miles till empty, with 1/2 tank left. there are TONS of places where you're going way more than 100 miles between fuel opportunities. EXO tends to keep a 55 gallon drum of fuel in the chase truck just in case.
I'm sure, if it is possible to pull off, S&B will have a larger fuel tank for it, but I don't know how likely it will be to cram a 60 Gallon tank in it. ( and by comparison, my heavy ass super duty gets about 600 miles out of its 60 gallon tank when offroad. It might not have all of the ponies that a TRX does, but it does put down 1000 ft/lbs. )
Make no mistake, I legitimately want the TRX to work and be successful. Competition breeds innovation. I just have serious reservations about how useable as a legit offroader the TRX really is.