I've become a HUGE fan of my new 2016 F150 with the EcoBoost Engine. It's a V6 with twin turbo's. When not towing it's getting 25-26 mpg on the highway and 18-19 around town. My old 2003 Ford Explorer with a big V8 didn't have near the horsepower, was a lighter vehicle and was lucky to get 16mpg around town.
I've only towed one weekend so far with the rig in my signature, in the north Georgia mountains, but I was very impressed to run from 10 to 12 mpg. I suspect on flatter ground (say headed to Florida) I could pull 12 - 13.
I use the trucks computer to track mileage. The new Ford Sync 3 system has 2 trip monitors, each tracks gas mileage separately from the overall mileage number. So it's easy to track what you're getting while towing and not towing.
Back when I still had the V8 Explorer we did a LONG, 8k trip out west. I carefully tracked mileage on each tankful. I became convinced of two things.
1) Wind direction has much more effect on mileage than I expected - going across flat Kansas wheat fields, headed N to the Dakota's we were getting almost 16 mpg with a tail wind. A week later, coming home, south across flat terrain but facing a stiff wind we were having trouble keeping 8 mpg.
2) There IS a difference in gas. I know the stuff about "it all comes out of the same pipeline" but running in the same terrain and same wind, I could see several mpg difference between gas bought at "no name" stations and gas bought at BP, Chevron, etc. And they were all rated at the same octane.
Buddy Ray - Atlanta
Jayco 2016 Eagle HT 26.5RLS
Ford 2016 F150 Lariat, 3.5L V6 Ecoboost
Max Tow Pkg, 36gal tank
Reese Sidewinder and Reese Titan 16k hitch