Just finished a 825 mile drive from Texas to Colorado. Lots of flat ground with some side winds. I was the only one in the truck along with 2 tires mounted on wheels laying in the bed.
First tank I kept the speeds at 62-65 mph and averaged 20.1 mpg.
Second tank ran 69-72 and averaged 17.3.
I suspect if you had the patience to set the cruise at 55 you could nurse 22-23 mpg out of the truck.
Truck is a 5.7 CM 4 wd. Your mileage may vary
First tank I kept the speeds at 62-65 mph and averaged 20.1 mpg.
Second tank ran 69-72 and averaged 17.3.
I suspect if you had the patience to set the cruise at 55 you could nurse 22-23 mpg out of the truck.
Truck is a 5.7 CM 4 wd. Your mileage may vary