With 9800 miles on it, we made a 300 mile round trip last weekend. Overhead was reset with fill-up when we started, overhead balanced out after about 20 miles and at the end of the day, it said 21.5 MPG. Took the truck down the next morning and filled up again. Put pencil to paper and came out to 21.1MPG. Running cruise on the highway at 77 MPH unloaded.

 

So far, avg 16.2 mostly around town. looking at the overhead, reset it once when I left the dealer with 6 miles on it.
But I only have about 1300 miles on it.

Rich