I recently made a 400+ mile trip 95%highway and avg about 17mpg. Which at first i thought how ****ty it was but than i thought well i do have twin turbos and 6klbs doing 75-85mph so im pretty happy.. best was 19 worse was 11mpg. 13 eco screw 2wd 3.31s on stock 20s, mpt93 race tune, 11,600 miles

 

Yeah it's an ios app. Roadtrip LE

 

19.5 mpg based on my computer.

 

I have had my truck for about 6 months now, my old man has had his since 2012, and what we have found is fuel with the "up to 10% ethanol" kills the power out of the ECOBOOST engine and ruins the mileage.
My dad had realised this when he bought his and the dealer said nothing about it nor did mine when i got it this summer. Ignorantly for the first couple months i was buying the 'cheap' ultramar gas with the added ethanol and i didnt notice the slow loss of power and mileage, until i took my dads truck out and noticed the huge difference in response and mileage. I asked him about it and sure enough he went through a similar situation.
I emptied the tank and filled with supreme(with cleaning agents) and within a couple km i noticed a huge difference. Responce has come back(no sluggish push from stop) and mileage has improved.
If you are not one who checks for these things i highly recommend thowing some 'clean' fuel in and see the difference.

Mike

 

I calculated my mileage recently after doing a slew of highway driving vs the normal, mostly city as of late, driving that I have/had been doing. I've tried higher octane gas, as well as simple 87 - nothing changes. I'm lucky to break 12mpg .... when I say a slew of highway driving I mean driving from San Antonio to Tulsa for example for Thanksgiving. Then loads of driving to further south Texas for deer hunting season. Basically what I am saying is I've been trying to make rhyme or reason of this since November so it's not like I only started a day or two ago...

The only mods to my 2014 FX4 Crew 5.0 is a leveling kit and one size larger tires (went from 255->265). Granted the tires are 10 ply Toyos, but I'm having a helluva time assuming that the additional weight from those alone is causing that much havoc on gas mileage...

I've not gotten a tuner yet as I have no idea which one to get - no research done yet by me.

Ideas? Thoughts?

 

By the end of my tank my computer put me at 18.8 but the pump/mileage is 16.8.

Is the computer really that far off?

 

Leveling and bigger tires will for sure effect it (1-2mpg) however your does seem fairly low, could be numerous reasons. Are ya a led foot lol? Its a 2014, i would bring it to the dealer and ask them about it, could be something else like dirty MAF or spark gaps. Good luck though

Mike

 

Dirty Mass Air Flow how many mile = that? Would the gaps make a Real difference?

 

Another thing you need to thing of is how cold the ambient temp is, I've noticed in my '13 SCREW 4x4 Tx edition, that when the temp is below 60 my mpgs will be in the 15-14s and they're usually in the 18-19 range @70 mph

5.0L with 3.55s (I guess)

 

Yeah, I'm also curious how many miles one has to drive (granted, everyone's conditions differ) for the MAF to become dirty. I've got roughly 9K on it as she sits nows. As for the gaps, I wouldn't think they would've changed in that low of miles but I suppose anything is possible..

Looking around on Amazon, etc... looks like a replacement sensor CAN be as little as ~$50.. can of cleaner appears to be much much cheaper tho