I have 2001 F150 Screw 4x4 with the 5.4 liter V8 and I get around 15 MPG with about 3000 miles on the truck. That is with a mix of highway and around town driving. I also commute about 30mi round trip to work. The mileage seems to be improving as the truck breaks in so don't be discouraged if you don't get good mileage right away. I also would NOT get the 4.6 liter in a Screw to try and get improved mileage. Its just to heavy of a truck to get good performance and towing capability with the 4.6.