OP.. My Dually V10 gets 9-10 mpg mixed driving. Maybe 11 if I behave 100% (never let the tach get over 2000 rpm.) Towing is 7-7.5, with one tank getting 8.5 and I am not sure how that happened.
The reports of the new 6.2 are a bit better than that.
My perspective and situation is a little different. I had a NICE (as in cream puff sweet) 1997 F150 extended cab XLT 2wd. It was my daily driver and I really enjoyed that truck. (My favorite vehicle ever) It handled my current trailer very well (that old 1997 had a 5.4, 330 lb ft of torque and a 4 speed auto transmission, 3:55 limited slip) The boys outgrew the extended cab so we "upgraded". We camped all the time.
Thought we were going to be upgrading to a bigger trailer. (You know, the 10,000-12,000 lb fiver thing) and we needed a crew cab for the kids. Our trailer has a GVWR of 7700 lbs, but fully loaded for camping we are at 6500 lbs. Dry weight is right at 5000 lbs. I am not sure how I can get 1200 more lbs in it. Now we know what we would buy and what we want in a TT. The dream trailer has got a GVWR around 8500 lbs, quad bunk with a super slide. I am not so sure that all travel trailers run around at their GVWR. But that is for a different thread.
So, what did we do, sold the sweet and capable half ton, for our current F350 Dually. I have done everything in my power to enjoy this truck but the simple matter of the fact is that I don't. I don't hate it. Its just doesn't fit my usage and its flat uncomfortable. Since I live in the Rural Country to get to the "Big City" is a 45 minute drive. In other words, it cost me $30-40 in fuel just to take it into town. ...once!!!
We camp LESS now, mostly because of fuel. My F150 was a daily driver, this F350 is not. Its an uncomfortable dedicated tow vehicle that mostly sits in the yard with about $20.00 in gas sitting in the tank. I now have a DD and a Dedicated Tow Vehicle to maintain and fuel. Being a growing family those two vehicles really cut into the camping budget.
If I had to do it again, I would have simply bought a newer F150 Super Crew with the Max tow package. Would it be maxed out? Maybe, I am not 100% sure. But for the 98% of the time I don't tow it would have been Perfect. For the other 2% it would have been adequate and capable
What I am saying is be careful, consider EVERYTHING. (and it sounds like you are doing a great job of that)
Yes, pulling the trailer with the dually is nice, but I still have to pay attention to the details, I still have to mind the hitch, break control, air pressure (which is a pain now with a dually)
Yes, the F350 and the Town Car are probably going up for sale in the near future ;)
Good luck and let us know what you decide to do.
Thanks!
Jeremiah