We just traded our 35' Jayco for a 37' HR Alumascape quad slide.

We got an average of 11mpg towing the Jayco from NH to AZ. Never lower than 9.5 (headwind and mountains) or higher than 13 on flat running observing the speed limits along the way.

The Jayco was 13500 GVWR, the HR is 14400 normally, but I opted for the 7k axles so the optional axles boosted that to 16900 lbs. I have yet (on the scales) to load heavier than 14k. I expect the mpg to be about the same as the height of the 2 fivers was the same 12' 7".

04.5 LLY 2500HD extended cab

I love this truck and that's from a lifelong Ford owner.

Mark