80 mph on I-10 I get 22.6 mpg on 93 octane.

 

My 2013 GT Premium with Track Pack only got around 200 miles on a full tank of gas. Drive 50 miles city driving and you eat up quarter of a tank. As the car was driven mainly in the city, only got around 13-14 mpg average. I did see 27 mpg while on the freeway at 50 mph once, but overall, gas mileage was terrible to me. Car is bone stock, and is a stick, obviously.


That's why I got a 2016 Nissan Versa Note as my daily driver. Gets 35-36 mpg during 40/60 city/highway driving.

 

I get 23 MPG at 80 MPH with a supercharged 5.0.

 

I think we're all pretty convinced there's something wrong with OP's car.

 

Seems like the OP left town...no more posts from.

 

I think her car is a V6 to boot she replied it wasn't a GT in her second post.

 

She must have a Shelby

 

So far you complained about 10 MPG but then you say the computer is telling you 19.9, that is still better than I get when driving in town. Also getting on the freeway for 100 miles after just driving in town does not give it enough time to adjust and get all the carbon out.
You need to hand calculate you MPG, mine has been as low as 12-14 staying around town and as high as 34 on the highway.

 

I have 3.31 gears, which makes a difference. 75% highway driving. Usually shift between 2,750 and 3,000 in normal driving. I’m in 5th from 35 mph and up in normal driving. I have plenty of fun when I’m out of the city too

 

Yeah, I've decided to swap the 3.55 gears that came with the performance package for 3.31. Trading a little acceleration for better mileage makes sense with the amount of highway driving I do. Might help me keep out of trouble too.

 

Been doing mixed driving here. Some freeway at 70-75, but a lot of city & stop and go... Been getting 15.9 according to my car computer. Been steady all summer. I am running a Ford Performance Trackey tune, with 91 octane non-ethanol. I use the trackey pretty much all the time.

Not sure what they mean by two tanks? It is not an F-150.

 

I don't think it actually has two tanks, actually one tank that is split in the middle by the driveshaft. Apparently there must be some issue on some cars where gas gets stuck on the other side where the fuel pump can't get it?

 

My car is an early-2013 (special ordered, delivered May 2012) so its not compatible with Track Key, but I do have the ProCal tune which is pretty much that tune (mostly). When in CA, I run 91 octane (highest normally available at stations). When in MA, I run 93 octane (available at pretty much all stations). I also have CORSA X-Pipe and CORSA Sport Cat-Back (and headers waiting to install).