Got this today, a steady 55-60, for about a 10 mile stretch, 2018 F250 4x4 6.2 with 4.30 gears... need to verify with a refill and divide miles/gals..

 

I get 18 mpg at 60 mph. 2017 F350 4X4 6.2 4.30 rear end

 

If I keep the RPM right on 1500, I'll average 23 mpg all day on the highways.

 

 

Do you believe the lie-o-meter or have you verified its accuracy with your own calculations? Mine was quite optimistic and my hand calculations determined the true MPG value was only 93% of what the dashboard had been telling me. Fortunately, you can adjust the MPG settings. The following post is in the FORSCAN thread, but you do not need FORSCAN to make the adjustment.
https://www.ford-trucks.com/forums/1...l#post18097223

 

I can get mine up to 26-28. But I have to set ACC to kamakazie close and find a tractor trailer to draft off of at no more than 60MPH.

 

I can get my 2018 F450 above 20mpg for 10 mile stretches also. But I eventually have to stop, accelerate, or climb a grade.
the average of 3 full tanks (minimum), hand calculated, is the only way to really tell your true mpg.
I kept a log of every fill up on one truck I owned. Often I would get a really good or bad mpg, the the next tank would be the opposite.
there are way too meny veribles to know true mpgs on just one tank, or one 10 mile stretch.

 

This is a gasser..