So last weekend I did a little experiment to answer the same question about what an Ecoboost is capable of, mileage wise, if driven very conservatively. I was on a trip, and stopped about 90 miles from home and filled up with regular unleaded. Calm wind and 50 degrees outside. Mostly flat terrain.
2023 EB AWD with 4K tow, and tonneau cover. 4 k miles on the truck.
Just to see what the truck can do (obviously not normal driving for most) I set the cruise to 57 mph, and kept it there when the limit was 55 or over. Drove the limit on roads less than 55 mph. Soft accel from stops.
30 miles of 4 lane - 70 mph speed limit.
40 miles of two lane - occasional stop signs.
20 miles of collar-suburban driving. maybe 15 stoplights.
I pulled into my driveway with 40.1 mpg shown on the tripometer. Driving normally for me, (like 9 over the limit), I average 32-33 on the same trip with the same conditions.
These trucks mpg (like most vehicles) are VERY sensitive to how you drive them. This is why you read posts about some people getting 25 mpg, and others getting in the mid 30's, and insinuating others are lying about their mileage. No one is lying, just driving the trucks very differently.....