 I ended up buying the 3.5 Ecoboost.  I was skeptical at first because of actual fuel mileage reviews.  My trip home, IMI showed my average at 23 mpg at 65 mph.  Then it shows I'm getting 16.9 driving in the city.  So far I am extremely pleased.  I will also recommend buying from Murray Ford in Starke, Florida.  My salesman was Anthony Sweat and he had to work to find a truck with the exact options that I wanted.  They were great and also have a 15 year...150,000 mile power train warranty.  The truck runs and rides great too!