Crossing Wyoming on route 80. How steep?
Sorry, Larry, the GCWR of the vehicle is how much you can carry/tow safely. It does not guarantee you won't find it challanging. Diesel
engines generally will pull the maximum load without difficulty, but all but the very biggest gas engines can be unpleasant towing up hills.
My trailer is less than 2/3 of what my truck is rated for, and it is rock solid pulling and stopping. However, the midsized gas engine of the truck has great difficulty pulling the trailer up any grade at all. As soon as I hit an up grade, my speed starts dropping off, and if the grade is long or more than a few degrees, I can't maintain speed whatever I do. I'm guessing the highway in question is 'similar' to I40 between Amarillo and Albuquerque, which I had an unexpected amount of trouble with.