My first tank was 13.9 combined driving. This is my calculation and not the vehicle's guess. I'm not sure how full the dealer filled the tank though. This time I filled it so I will know more when I fill again.

 

Just under 600 miles on my 2009 Screw 4x4 5.4L w/3.55's...dash says mixed driving average at 16.6....after my first fill my math came out at 17.75. Live and drive in New England...many hills etc... keeping my foot out of it for the most part. Can't wait to see how it does down the stretch...my 2003 Ranger was only getting 18 on a good day.

 

Better take a pic of your odo before and after, and the pump redout too, since the dash display dont amount to a hill of beans most of the time. Well I suppose i shouldnt say that, mine is pretty consistant, just way off by the exact same amount each time.

If your going by the computer too, make sure your going by the average for the whole tank. Even my big V10 F350 I can get the display to show 18MPG even after many miles of driving, but not a whole tank. I fill it up and reset the guage then drive home (about 20 miles from gas station), even on the windey country roads byt the time it gets home its still 18+ if I keep the speed down and coast to the stop signs, etc. But after stopping it and restarting in the morning, and a few more trips it always comes down into the 15's even though the drive is pretty much the same. And if your going on a long trip, it would be more accurate to try to average to and back since most of the time youll have wind or elevation helping you one way and hurting the other. So one value will be inflated and the other way hurt, average the two. I can believe low 20's for these trucks but a repeatable 25 is hard to beleive. Your in 4-banger ranger territory there. And if its true then those EPA ratings are way off!

 

That's interesting... even the 5.4 running E85 only claims 320hp...

 

Why so interesting? Who would burn that crappy E-85? 210HP bone stock, chipped with intake 330 lol!!! I can see why your the big posting guru, with all the stupid questions lol!

 

Ahh, time to invoke a piece of wisdom from my past - never argue with an idiot; he'll drag you down to his level then beat you with experience.

 

I have 590 miles on my '09 F150 4wd crewcab with 5.4 and 3:55 rear and still have a way to go till "broken in " but have seen a low of 16.8 to a high of 19.6 mpg. according to the on board calculator , which is better than I expected . Got some more mods to make on her yet { only a cat-back exhaust has been done so far } and am hoping for even better mpg's ?

 

Don't forget any alcohol blend will result in lowered MPG. My '08 last year with a couple of grand on the odometer did get a respectable 20+ MPG during a section on the interstate doing 75-80 coming back from WDW burning 10% blend.

 

i have 2800 miles on the odo and have seen a high of 19.8 (highway with the wife driving, i am usually right around 18.5) and a low of 16ish

 

09 FX4 5.4 with 3.73 gears 10500 miles it is averaging 18.9 mpg combined mostly highway driving at 70mph.

 

Something must be wrong with mine. I have 470 miles. I am averaging 12.9 to 13.1 average driving. ( empty ) I haven't towed or hauled anything yet. Some highway- some city. I am driving @ 75 -80 on hignway.
I am hoping that it will get better. So far this is worse than my 2008 F250 6.4 diesel.

 

75-80 on the highway is part of the problem... do you have 3.73s too? I have a 6.5' SCrew 4x2 with 3.73LS rear, and the gas mileage drops off precipitously above 70-72MPH.

MPG comparisons are largely useless anyway... what elevation are you travelling at? Are you easy on the gas or hard? I could take two identical trucks in two identical runs and get several MPG difference based simply on gas/brake usage.

I drive in a spirited manner and enjoy it, but am cognizant of the fact that I could easily get better gas mileage if I wanted to. I also have equipment on my vehicle which tends to hurt gas mileage anyway.

 

I was just getting ready to post something to the sort. When it comes to people and their MPG I have only one thing to say:

"Believe nothing of what you hear and only half of what you see" and you'll be pretty close to the truth.

The guy around the block gets 18 MPG highway with his 09 F150 with the 3.55 gears and 13 city.

I think he's more believeable.

 

With 2500 miles on my 09 XLT with 5.4L and 3.31 rear end mixed mileage is at 18.5 and early highway went from 20.1 to 21.0. Added tonneau cover and currently getting 23.0 expressway (65) and country roads of western NY. I am a believer, the tonneau makes a difference. Don't know if there is still a break in effect.

 

My 2010 Screw 4X4 5.4 w/3.55 got 16.8 (hand-calculated) on the first tankful. Getting near fill up time again and it looks like it should be close. However I live out of the city and have more open roads, no rush hour and less stop-and-go driving. My other truck (F-250 crew with 6.0) averaged almost 17 mpg (hand-calculated) over 80K miles; but since my son has been using it in the city, he's only getting slightly over 14. So to me it seems that miles per gallon can be as dependent on driving conditions as on your driving style.