OFDPOS wrote:
Thinking maybe a little more aerodynamic without the big overcab sleeper on the C's?
The bigger C's on Ford, seem to get 7.5 to 8.5 maybe 9. That Aspect is lower and narrower, as well as smoother with a fairing instead of a cabover.
It's also new enough to have a TorqShift, at least a 5-speed. I don't know when they went 6-speed. But with Tow/Haul, you don't have to go "OD Off" like we do with the 4-speeds when the going gets hilly. 
I've driven Tow/Haul Fords and it was nice. I think my term was "Smarter than a Trick Pony" but it seems from other comments here that the Ford Cruise Control is still finicky with TorqShift, just a little less than the Very Finicky it is with 4-speed 4R100. To me, using my own foot, letting speed pick up on down grades and dropping on climbs, plus avoiding SO many downshifts on Cruise, is good for at least 0.5 MPG better.
So my projection is 9-to-11 at reasonable speed, mixed but not mountainous terrain. Hopefully real owners will chime in, and the news will be better than my guess.