Fords method of small displacement (mine was a 2.7) being asked to move a full sized truck means you are into the twin turbos a lot. Thats why they dont often get the claimed mpg in real use. If you are towing or even have much in the bed, or if you are in hilly country then you are spooling up those turbos.
Its like back in the day when 4 barrel carbs had small primaries, drivers found themselves into the secondaries too much and mileage went to crap. Except now its stress on the engine not just mpg’s.
Ford has a huge investment in their “ecoboost” technology and while it has excellent power/torque, it is working those mills hard! I mean their largest ecobost (3.5) is the size of the Pentstar, and their V8 (Coyote 5.0) is less displacement than the old 5.2 Dodge. All that makes for hardworking motors while the hemi sorta’ loafs along.