Stock with cover and about 18k miles. Average combined is 16mpg. If I can stand driving slower than traffic and set cruise control at 60mph than I have seen 21-22mpg, only did that on a 250 mile trip, couldn't take it anymore and went back to 70mph and 18mpg.
Put 250 miles on today with 95% going 55mph. computer said 21.3mpg. Haven't filled it up since I got back to verify how close that is. I've got the 5.0 super crew with the 3.55 gears. Truck now has 500 miles on it. I'm looking forward to seeing what it'll get once she's broke in
Recent round trip to Alabama from Illinois was 99% interstate driving,920 mi.Used cruise whenever possible. Lowest instant milage was 19,best was 20.5. I set cruise at 70 mph. I have a 2011 f150 sc,4x4,5.0,3.73 gear. My intown average is 17 mpg. Milage has improved since 10,000 mi. and has probably peaked.
Just finished a 1230mile trip through northern ontario (constant rolling hills). Cruise was set between 62-65 mph (trans canada highway is only 55mph on that route) with probably 150 miles of the trip going through towns and construction areas (sometimes stop and go, other times just drop speed down to 45-50mph). Wind wasnt really a concern.
Truck is a 2012 screw fx2 5.0l with 3.73's and 20" rims (has 3000 miles on odometer now)
Overall fuel economy was 20.8-21 mpg. Seems my odometer is out by about 1% from the measured markers on the highway