Truck trends one year with ecoboost 14 mpg average

I put about 20,000 miles a year on my 2012 ecoboost. Half of these miles I carry a quad and equipment in the box totalling 700 lbs. My mileage doesn't vary whether I am loaded or empty. So if the 2015 Ford F150 is 700 lbs lighter I wonder what difference the mileage will be with the same poertrain. I average about 17 m.p.g. with 1/2 highway and 1/2 rural with very little city driving. Love the power but I got better mileage with my 2010 F150 with the 5.4 V8 powering it.