Time to take it in to the dealer.

 

Everything is completely stock on it. It has 3.31 gears and whatever tires come with 20" wheels.

 

You need more miles on it before you get to bent outta shape. Most of us got great mpg straight off the lot , however not everybody sees the great mpg from the start. I get 20 in my 11' EB FX4

 

That is some crazy low numbers man. My '13 fx4 with 3.55's overall averages 17.6mpg mixed driving and @ 70mph on the highway 18.5ish with 3,300 miles on the clock. If that huge gas tank is nearing empty on the truck i've seen over 19mpg on the highway. I have yet to see anywhere close to 20mpg on the high way with the cruise set @ 70 like some people but im happy with the 17.6 average. I'd be pissed if i was getting anywhere near 13 mpg lol

Strange question here, kinda off topic but can ya'll see my signature on my post? I can't see it when I post on a thread.

 

Mine has gotten decent mileage from the get go, but I also floored it for the first 100 miles or so to make sure everything was seated properly. It does seem like it has gained alittle power and some mileage since it rolled past 5000 miles. First tow of my fifth wheel was 9.5mpgs avg, my last haul it got 10.1mpg and the only difference was the truck rolled past 5000 mile marker.

 

You need more miles.......and beat it up once in a while. Mine has 3:15 gears and I'm getting over 20 mpg on the freeway, sometimes 25.

I didn't get any mileage until after 8,000 miles .

 

The 3.15 is a highway gear that's why your mileage is that good

 

The original posters gear is the same as mine.......

 

I know which is why I told him something is really really wrong lol

 

Just bought a new FX4 EB 3.55 20" wheels. (Edit the rear ratio from 3.31 to 3.55)

I drive about 40 miles to work (1/2 interstate - 1/2 state hwy with lights). I'm getting about 16.5 if I don't pay attention and drive easy. I usually get less 'cause I'm punching it from time to time.

If I really try, I can get right at 17. I'm hoping it improves, but that's about what I got with my 5.4 I traded in.

 

It seems most are getting pretty decent mileage no matter what their gearing is. I'm also on the low side. City/highway mix with 4500 miles on my 2013 SCREW and I'm routinely getting 13.5 mpg.. I don't set the cruise or drive at 60 but I'm also not hammering the throttle all the time. I've got a K&N CAI and run full synthetic ! The only thing I haven't tried was playing with tire pressure.
Like many of you, I've waited for that "break in" per to see if there was improvement but so far no luck.

This 13.5 mpg return has prevented me from any further upgrades.....(exhaust, tires, tuner) !
Just my two for those with the same crap from the less than EcoBoost !!

 

Many people have seen improvements in fuel economy from a tune. These engines run pretty rich with the stock tune. My truck gained about 1.5 MPGs with my Livernois 91 octane performance tune. I haven't tried the 87 octane tune yet. The 91 is too much fun.

 

I was just looking into the Livernoise tuner actually. Seems to be the way to go !! I also just checked out your truck and that thing is sweet. Just enough and not over built.
Im sure you've had a ton of tire questions already but I'm goin to ask anyway...hope u don't mind !! What size did you squeeze in there and obviously that was via a lift but what route ?? I just ordered a set of adjustable bilsteins but I'm just not sure what I can fit in there without having upper control arm issues. Not looking to go crazy as its a brand new truck and I really enjoy the ride as it is but it need a little help from stock !! The stock 275/55 is a decent footprint Ford started with but its still a bit short for that size truck.

 

Thanks...My tires are 295/60/20 (34.45") and I have 2" Autospring leveling kit (front only).

 

^^^^ nasty- try their 93V2 tune - it's super bad !