When you're cruising at 75 mph,,,,passing everyone,,, uphill,,, with camper in tow,,,, and you look down and notice the rpm's are at 1800,,,, you say to yourself "Self, buying a Duramax dually was a ...
I remember my first tow with my Cummins. It was a similar experience. I have to use Cruise control because I kept looking down and catching myself doing 80!