Drove from Effingham IL to Mt. Airy MD to visit the family and got great mileage out of my 5.4L. The best prior was 18.8 from Eham to Louisville and on this trip (Eham to Masonville, WV? where I filled up) I got 19.1. Pretty impressed, but wasn't pushing it to hard averaged about 74mph. All the MPG's are hand calculated the truck was telling me 20.1.