That's a tough question.....
With my new fuel injection and new 30 gallon tank, I'm having a hard time reckoning the mileage. I figured I used 20 gallons but that seems low. I would think a Scout with stock tank and 2 jerry cans would be fine.
I would think twice about bringing a carbureted rig on this trail. The altitude is very high and the climbing is steep.
Also, if I had my way, I would take 4 days to do this trail. It's that long and considering break downs, we could of used the extra time. I ended up busting my drivers side hub bolts (stretched and snapped) and the Jeep busted his cv joint (no spare) on his front drive shaft.
Moral of the story is to go prepared. This trail seems just easy enough till it catches you. Which is funny, the only scar I got was from a baby pine tree as I started to let my mind wander. Maybe next time I'll go with my Scout brothers and have to carry less spare parts.