What kind of gas mileage are you getting?

[allfivefifty]

I don't take too many long highways trips, but with the 3.73 gears on the 6th OD tremec I've noticed 25 MPG at 70 MPH and 23 at 75MPH. Florida so it's flat here for the most part so no need to account for elevation change. I did remove the lower chin spoiler and the gurney flap.

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[SheepDog]

9

 

[Ironhorse17]

I forgot to mention that I have 3.15 gears now, and want to install 3.73.

I would imagine the mileage will only get worse.

 

[Skye]

A few months ago I bought a 2017 GT premium auto with 128k on it, and I'm getting 8.2L/100km combined. The car has 135k on it now.

I am wondering if there's something wrong with the car. A local racing shop says without an error message, there's technically nothing wrong with the car.

8.2 L consumption per 100 km is 2.1 Gallons per 62 miles. So, 30 Miles Per Gallon (MPG) for a GT.

https://fueleconomy.gov/feg/bymodel/2017_Ford_Mustang.shtml

The reference is to the US fuel economy standard for the 2017 Mustang. Thirty MPG exceeds the combined fuel economy (it's even more fuel efficient) for a GT by several miles.

You bought the car used. I'd start by clearing the trip odometer and fuel economy data in the computer. Look for this in your owners manual. After resetting, fill up the car. Run through one tank and refuel. On paper, calculate out the fuel economy. Verify that against the trip computer to confirm they match. If you continue to exceed the standard, it'd be worthwhile to find out why, yes.

Your mechanic is somewhat correct: without a code, it's difficult to t-shoot something that isn't erroring. But with other devices he could monitor or look readings involving things like fuel trims and the sensors themselves. Faulty sensors, poor connectors to them could be two causes. The car has a lot of miles/kms. Things wear out. Corrosion on the connectors could affect their operation. Could be something else.

Another thing to consider: if a tune is involved. You bought the car used. If the car used a tune before and was sold as-is, something with said tune could be causing these conditions. This is speculation on my part.

But do a manual check of the fuel economy first. If that confirms you're exceeding the ratings, return to the shop to discuss, or go to a Ford dealer and explain yourself.

Good Luck.

 

[2020 MagneticPP1]

Long highway trips, my car constantly gets 26-28 MPG, city driving, it depends on my mood lol, can range from 4 to 17 MPG.

 

[SCOOTT]

Like someone stated earlier, I got mine for the smiles, and I like to go fast. If fuel mileage was a concern then I would have bought something else. Running 3.55 and could care less about the MPG's, the light comes on I stop and feed the beast. Hop back on and drive it like I stole it!!

 

[MAGS1]

Since I just filled up…

 

[Ironhorse17]

Would I trade the car because of the milieage? Not a chance. I like the car. It's a keeper.

My '06 GT had to stop and syphon gas out every 350 miles because the gas tank never ran out. Amazing mileage! The 2017 isn't the same. Slightly more horsepower too. Driving modes are a blast. Who's the nut that installed "Line-Lock" in these cars?

The codes got cleared because the dealership I bought it from left a dead/flat battery in it and had to boost/charge the car to start it. They also had to change the battery when I bought the car. One of my conditions of the sale.

Now that I'm retired and over 65, maybe I'm just over reacting. I got nothing better to do.

I'll do a comparison between what the gauges say, and the gas bill.

Thanks for the suggestions, @Skye.

Thank you to everyone that helped.
Ken

 

[Gary_H]

Then the engineer in me comes out, and I still secretly monitor it (but don't share the info with the wife ... lol).

That's me right there!

I reset the trip counter when I got the GT350 last month - it was showing around 12 MPG. I've only driven a couple hundred miles so far and overall average of ~15 MPG. That's a 50% improvement over its 300 HP, 1,000 pounds lighter predecessor (see aviatar).

I am a retired engineer and don't drive much any more. Matter of fact I might not drive at all for days at a time, so fortunately fuel economy doesn't mean as much as it used to. If I'm planning a long trip it will be in my turbocharged 4-banger GLC300. It severely beats the Mustang in both capacity and fuel economy, but loses severely in the smiles per miles category!

Edit: Best I've seen is ~19 MPG when I first got it on a longer trip.

 

[BlkMach10510]

20.3

 

[jpalmerino]

“Alex, I’ll take Oxymorons for $1000”

 

[ShadesOfBloo]

I have a 2020 GT-PP with 6-speed (so 3.73 rear end). Driving it to work and running errands, I think I get about 19mpg. I haven't calculated it for a while, but I know it's not the 21.whatever the display is telling me.
I've gotten up to 25mpg on a 4-hour highway trip.

 

[ShadesOfBloo]

Florida so it's flat here for the most part so no need to account for elevation change...

Yep. If you're on the peninsula, your latitude changes more than your altitude.

I lived on the panhandle, and once I went to the highest point in the state.
I think it was about 330 ft above sea level. It was a hill with a picnic table on it, across the road from the Alabama state line.

 

[SBR70.3]

3-4 mpg. Seriously.


But that's because my car is on E85 and I'm staying >6K rpm most of the time. Track use.


If I do drive it city/hwy then it's about 13-14.

 

[awhitegt86]

I have daily driven my 2020 10R80 and always see 22-25 MPG combined. On long trips with two people and luggage, I can have multiple tanks in a row at 31-33 MPG. 3.55 Torsen and I never baby it.

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