Yeah, the diesels didn't struggle from a weight perspective, I can get up the mountain passes at pretty much the speed limit. It was more of a fuel perspective. Having to stop every 180 miles for diesel sucks. My 6.0 powerstroke got me 220 miles with the 29 gallon tank. Just traveling through Montana and the Columbia river gorge you really have to pick your fuel spots.
I am hoping to get closer to 11 or 12 mpg. My current duramax gets 20 at 60 mph empty, 18 at 75, 16 at 85. I track my mileage with an app, so these are actual, and all within a half mpg from my dash.
Thanks for the responses.