Having had my Ecoboost for over 3 years now and watching the fuel mileage closely, I can say that the fuel mileage is dependent on several factors. Fuel octane, whether its summer fuel or winter fuel, ambient temperature, pulling any weight, and driving technique all have noticeable effects on fuel mileage in regards to the Ecoboost engine. I get from 10 to 27+ mpg with my Eco. GENERALLY, in warm weather I get 18+ in normal combined driving, and in winter, its around 15. That winter fuel and lower temps make a big difference. Highway mileage is very dependent on speed. At <60 mph, I can get 27, but that is unusual. Normal there is around 24 with 87 octane. From 60-65, its 22 barely. 70 or over its about 20 -20.5. I did one run where I kept 80-90 mph for quite a while, and was rewarded with 14 mpg, but I wasn't very steady on the go-pedal.
Towed my 25' travel trailer for 3 weeks from Ohio to Arizona and back last September, averaged 11.1 mpg over the 4300+ miles. That was going about 63-65 mph most of the way. About the same towing as my 2005 F250 6.0 diesel got.
If those magazine guys (who are writers, not professional drivers) got only 14 mpg, they were wailing on it. Hard not to with all that power and low end torque.
