rightyouareken wrote:
I average 17mpg mixed city/highway. At 65 mph I see 21 mpg. At 75 mph I see 19.5 mpg. All unloaded. Towing I've averaged 10-10.5 mpg over 1000 miles so far.
That's what I'm seeing exactly! I haven't gone as slow as 65 mph on an expressway yet with it but @ 75 mpg I was getting 19.5 mpg exactly!
Haven't towed with it yet. I towed with my 5.4L, which was the same XLT Crew Cab 4WD except fewer options and a 3.55 limited slip axle opposed to the new 3.73 locking axle. I was getting 10.5 mpg average towing the 2012 Jayco 26BH. 
While the Ecoboost may do 1 or 2 mpg at best unloaded and not towing, it's usually the same as the 5.0L. It's been shown in the F150 forums that the Ecoboost will get about 1 or 2 mpg less towing than the 5.0L. Also don't forget it has less engine braking with the smaller displacement. Others have mentioned this as well but got used to it and used the brake pads more. ;)