Right ,but the l5P is not making 600hp towing and has alot more Management systems to pull things back where as James is literally just sending it with hsi right foot.
It doesn’t have the power but it has the cooling. He’s not using all of that 600hp. My friend tows his two car enclosed trailer grossing 24,900lbs and it’ll maintain 75 all the way to Kentucky from Ca. Not sure the % of the grades going up that way but he said the truck didn’t even flinch.