I am on my second 3.0 Powerstroke and zero problems. I wanted the new F-150 is the only reason I got rid of the previous 2019. I don't baby the engine and always keep up on maintenance and change the fuel filters every 15k or so.
So I have been away for abit some food for thought . This is non scientific So I took off the Tonneau cover for a 2 week time frame worst mpg was 20 best 23.5 . 16k 6 months later All hand calculated Big head winds with temps 30-50* F. 2 weeks later cover back on and same route speed etc 22-25. Many factor are to be included not just how hard you stomp on it. I expect the guy in a flat place with warm weather getting getting close to 30 all thing being equal . If I can average 25 for a thousand miles on a 80*f days being in hill country . Short trips 30 min or less not good for diesel owner but those long trips are good. I do expect to average 24-27 when I hit the summer .Being able to drive a gas equivalent I average 15-19 on 3.5