That's silly. The flamethrowers didn't help the guy in the left lane. I wonder what they run stock? They have a ton of torque for pulling stuff, I'd think they'd do halfway decent without a load.
My uncle ran 21.xx with an International Eagle, which was International's big truck back in the 90's. It only had a 350hp Cummins in it. You can get 600+ hp with 1800+tq in the newer trucks.