I had a 2006 CC SB F250 4x4. The GVWR was 9900 if I remember correctly. Payload was 2700ish lbs. 4.10 rear end.
That thing was a towing beast. I towed my 6000lb TT all over.
I once towed a heavy equipment trailer around town with a forklift on it - probably close to 15k lbs. It did just fine.
Best gas mileage: 15mpg - downhill, empty.
Worst gas mileage: 3mpg - uphill, headwind, towing 6k TT.
I got rid of it because mine had problems. I believe though that I had a lemon and that my problems stemmed from it having been rebuilt/restored. They weren't your normal wear and tear problems - instead it was things like the washer fluid pump wouldn't work because of the rat skeletons in the washer fluid tank. Yeah. That was gross.
