I got a 2021 F150, 3.5L Twin Turbo, 10 spd. towards the end of last year.
With a fair, at least quartering tailwind, it got ~23.5 mpg on 87 Octane E0 gas over 630 mi. today [self reporting..].
It can go over 750 miles on a tank of E0, under summer temperature, tailwind conditions.
With the lowest offered numerical axle ratio, it runs ~1850 rpm at 80 mph.
YMMV.
Drill, baby, drill....
I’ve got a 2021 RAM EcoDiesel Built to Serve, Coast Guard edition. Gets an honest 26.5 mpg city and 29.5 mpg freeway at 80mph. It’s got a 33 gallon tank and can drive all day. It’s one of the most comfy rides I’ve ever had, and I’ve had some expensive cars.