A few weeks ago we were having a thread about gas mileage. I, for one, was quite shocked and disappointed that my new truck (5.4, auto, 3.55LS) was getting only 12 mpg, on three consecutive tanks. I took the truck to the dealer to have the front end alignment checked, and complained about the poor economy. When I picked up the truck, he said they adjusted the steering, and installed a recent program update to the PCM (engine computer). When I touched the accelerator, the truck jumped to speed with pep it had not had before. I could tell the engine was running smoother, with less "labor" sound.
I decided to do a careful MPG check for a couple of weeks: 60 percent highway, 40 percent city.
17.4 mpg!!!!!
Get your PCM updated!! When Ford comes up with an update, do only complainers get it?

 

holy crap, that's sweet...McCotter Ford here I come!

 

In this a brand new truck or very low miles gas consumption can be a part of the engine break in period. Not saying that a PCM update wouldn't hurt, it's just sometimes they do use a little more and that can very truck to truck even if the variables are the same.

Just be glad your not a Cheby owner with that 8 liter of thiers. His MPG for past 2 tanks were 8.... I repeat 8 on a brand new truck. His dealer says it will go up to maybe 14 after break in.