Poor gas mileage question

[Kong76]

When you say 16mpg overall in your original post, I assumed it was mixed driving conditions. Now 16mpg at 50mph in sixth makes sense if you are only at that speed for say a mile or so. I have a 4 mile freeway trip every day but my mpgs stay around 15 because I am not at that speed for long term.

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[ChromaticGrey]

Forget what the computer is saying, especially if your are looking at the average which would include the previous driver.

Run a few full tanks, reset your trip mileage when you fill up note how many gallons you put in the tank when you re-fill and how many miles you drove with that. Work out the MPG the old fashioned way.

If you do mostly city driving or have a lot of stop and go traffic, 16 mpg seems fine. If your all highway, and driving easily and still getting 16 mpg, your not driving as easily as you think, or there is a problem, or somewhere in between. Nobody here can really tell you if there is a problem unless they are in the car and then see what mpg your getting, IMO.

 

[Silver Bullitt]

Where are your engine temps running after 10 minutes of driving? If it's running colder than normal, a thermostat stuck open can easily cost you 2-3 mpg, even more in cold weather.

 

[302@12psi]

Until you take the time to do the actual math and not rely on the CPU you'll never know.

Mine is 1-2 MPG in the plus. There's a Forscan Code posted here how to change the CPU settings. Perhaps someone changed it to try and get it more accurate.

Take the time, drive the car, do the math.

 

[frank s]

Tire size, tire pressure, and wheel alignment all have influence on mpg.

 

[ugstang17]

Your 18 has a completely different fuel system on it and advances in design over previous models. Comparing oranges to apples. While trans and gearing may be similar as well as engine displacement that is where the similarities end with regard to making a fuel economy compare. ECU upgrades have also been made between 17 and 18 models as well as other advances that may effect the cars MPG performance.

Forget what the computer is saying, especially if your are looking at the average which would include the previous driver.

Run a few full tanks, reset your trip mileage when you fill up note how many gallons you put in the tank when you re-fill and how many miles you drove with that. Work out the MPG the old fashioned way.

If you do mostly city driving or have a lot of stop and go traffic, 16 mpg seems fine. If your all highway, and driving easily and still getting 16 mpg, your not driving as easily as you think, or there is a problem, or somewhere in between. Nobody here can really tell you if there is a problem unless they are in the car and then see what mpg your getting, IMO.

See reply 13 - Thanks for the support! LOL!

 

[Islandstang]

I only do city driving ( island) and I get the same gas mileage in my 17 f150 5.0 that I do in my pp2
Around 11-12 mpg but I do have a heavy foot

 

[GregP27]

If you research the Mustang GT 5.0, that's about the mileage you expect. It's better than my 2007 V8 4WD Nissan Titan truck gets! And, it's about what I expect when my 2019 GT comes in.

 

[66Bronc1]

I'm going to guess it's the tune- tuned combined with the exhaust- tuned for power and not MPG. Also tire pressure and alignment as already mentioned. My 2018 does really well on gas- 25 around town and 30 on trips- but I also drive with a very light foot and accelerate slowly- most of the time. I also run higher tire pressures- 37-38 front, 36 rear.

 

[MPotter]

With my '15 GT with 6 speed auto, I've noticed about 3 mpg increase in average, calculated (not gauge cluster report) gas mileage when I use the paddle shifters as opposed to leaving it in full auto. I tend to drive more aggressively when using the paddle shifters, as well, so I was a bit surprised by the better mileage.

Edit to add that my average now is 21 mpg

 

[Cardude99]

You bought a GT what did you expect? 426 hp, 16 mpg isn't so bad. My Hellcat averages 10

 

[bless0]

I have a 17 GT PP with the JLT CAI and Roush axle backs, a very similar setup as the OP. I work from home so most of my driving is to the grocery store and back and to run a few errands. My fuel average is dead set at 16mpg. I only notice a difference when I jump on the HWY and I reset the trip computer. Then I average about 24 MPG cruising.

 

[Ghost50]

If I am strictly city driving then I average 16. Which I am fine with because even in my F150 that is what I get (even on highway). When I am highway driving the highest I have gotten on the Mustang is 26.

 

[5pointOh]

I am guessing he is referring to the instant MPG readout and not his average MPG. With that being said, 6th gear @50mph is lugging the engine pretty good if you are doing anything other than maintaining speed. My 2019 GT PP only has 200 miles but the instant MPG sits around 28 cruising @ 80mph in 6th gear. I'd have to try it out but I'd think the instant MPG for 50mph in 6th gear would be 35+ easily.

 

[David Schmidt]

I like very much the effect the loud pedal has in my '18 GT. I get about 16 MPG going downhill with a tailwind. I've said it before... if I were concerned about MPG, I'd be rockin' an EcoBoost...

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