That's what your going to get with it is what it is

 

This (although i would argue that the 3.31 does not hurt, actually helps on freeway). My 16 lariat is showing ~15 @ 6k miles. Have seen 18 averaging 70+ on freeways. But when I come over the pass it drops quickly. Still better than my 14 FX4 that showed about 13.5-14 over 19k miles. Bear in mind also I live at 6500' so that has an impact (and is also why the 3.5 works a lot better than a 5.0 for me) . And the 14 didnt get better as it got run in

So yeah, sounds about right

 

The fuel mileage stinks for these trucks. Ford's advertising of better fuel mileage isn't true. I have 3,900 miles on my truck and always average at 15 mpg. On every car I've ever owned I have been 1 mpg better than the overall mpg on the window sticker and with my F150 I'm 2 mpg below the overall average on the sticker.

 

I'm getting better than advertised with 34.6 inch tires. Lol that's a hair over 17 mpg and getting better.

I haven't done any towing yet though.

 

I only have 803 miles or so on the truck. My first fill up I had 17.24MPG hand calculated, and this second trip I had 17.63. Granted most of mine is long trips around Texas (read 190 miles at a time)

I have a SC with 6.5 bed with 3.31 and the 3.5 eco. Even if this is break in period, I still have far less miles than you and still getting better fuel economy. I would check tire pressure.

 

2016 XLT screw 3.5eco with 3.31's. City driving im averaging 15. highway at 60 to 65mph i'm seeing 20. if i get anywhere near 70 I'm only seeing about 17 but i can do 80 and still get 17. I have just shy of 1000 miles on her. I towed my trailer with three 4 wheelers to the lake last weekend 250 miles and got 14mpg. I've gone through 2 tanks of gas and calulated both the old fashioned way and they are spot on with what the truck is telling me.

 

I'll throw in my 2 cents. My first tank on 500 miles break in period I got 19 mpg as reported by the on-board computer, mixed driving and not going over 65 mph.

Now I'm using Fuelly to monitor my fuel economy. I've had three more fill ups, my avg is 21 mpg and best is 22 mpg (long highway trip going between 65 to 70 mph.)

I have a 2.7 scab, 265 tires inflated to 40 psi.

One thing I've noticed, the on board computer is about 1 mpg higher than actual. Anyone else notice that?

 

That's pretty impressive for a Frontier, assuming it's an automatic. It seems the only people that can get decent fuel economy in those have the 6 speed manual transmission. I have to BABY my Frontier to get up to 18mpg, I'm probably at a lifetime average of 16.5.

 

Yep - says so right on page 179 (of the manual, not the PDF)- see http://cdn.dealereprocess.com/cdn/se.../2016-f150.pdf

 

You have to understand something about the ECOBOOST and turbo engines in general. While the small displacement engine is a wonder, it's only good on gas when you aren't spooling up the turbochargers. It's very easy to apply generous amounts of foot to the pedal and as a result, your mileage will suffer. Select the boost gauge in your cluster over transmission temperature, and keep it out of the blue. You should see an improvement in mileage. We often joke on the forums that you can have ECO or boost but not at the same time.
Also, keep in mind that the configuration you have is heavier than most, and as a result you'll have reduction in MPG for that. Lastly, keep in mind that the computer likes to report average MPG. It doesn't break down highway and city driving. Things like leveling, larger / heavier tires etc. also can have a radical effect on mileage. I dropped from 17MPG average to 14.3MPG changing the tires, adding a leveling kit and a bull bar. One final note about fuel, you can't just swap between fuels and expect to see a difference. You need to stick with a given fuel so that the short term fuel map values become long term ones.