Rivian Electric Truck takes on the Ike Gauntlet

I was involved in moving a portable crusher a few times. Their powerplant used the same engine as I had in my truck. (3406E) When I noticed the small fuel tank, I asked how often they had to fill it in a shift. "If we run over 12 hrs, we add fuel to be safe". Working my truck, 6 hrs would be the safe point. Running only at most efficient speed, instead of working with changing road speed must make a difference