BurbMan wrote:
First road trip 2 weeks ago, sadly no camper yet, but was loaded up with RV parts from the Elkhart surplus stores!
Had the cruise control set on 75 for most of the trip, LI to IN in about 10 hrs. Laramie trim makes for a very comfortable ride, although a little bouncy, need that 3200 lbs of camper on the back to smooth it out!

You must have been bucking a head wind. Mileage should have been higher, based on my experience. Was the load above the cab? What was hand cal mileage? The tires now on the truck could be effecting mileage. My lie-o-meter always shows better mileage than my hand cal mileage. I always use the two additional clicks when fueling. First additional gets a little more in, second clicks off right away.