Bill_Texas

Greetings and Happy Holidays to all.

I have owned my 2011 Mustang GT for about 6 months. It is my daily driver and I drive it approx. 56 miles per day mostly highway miles. What I am finding is that the advertised 26 mpg highway appears to be false. The computer is showing that I am averaging 20 mpg. Simple math is showing similar results.

I have heard other similar complaints on other formums. I am beggining to think that this is false advertising by Ford. My goal is to find out if I am right by asking anyone out there to post their estimated mpg results as well.

Thanks in advance to anyone that responds!
Bill

keoni1984

I've noticed the same with my 5.0 (6MT w/3.73), typically 20-21mpg average on the computer.. but I was attributing that to my lead foot. It will go up 2-3mpg if I do EXACTLY the speed limit.

JIM5.0

If you have 3.73:1 rear gears, yeah, the fuel mileage will not be the advertised 26mpg hwy.
Also, you car will improve in mpg once you reach 5000 miles.

I have 3.31:1 rear gears on mine and on straight highway at 70mph, I get 28mpg. I have seen on rare occasions 30-31mpg average.

What destroys fuel mileage are stop signs, stop lights, and speed limits less than 60mph. City driving. In city driving I see high teens mpg avg.
Mixed hwy and city I see 21-23 mpg avg over a month time.

clowe1965

held an average of 22 for a few weeks (mixed, 60/40 city/hwy) (man. 3.31). If you want to see the 26 mpg reset the avg mpg meter on the entrance ramp. These cars, when driven appropriately as Jim5.0 indicated, will get the advertised mpg. I'd like to know how he got the 30mpg. I got 27 on the way up to charlotte 3 weeks ago by resetting the meter. Does anyone know if the computer uses a rolling average, and if so what is the interval that it uses?

JIM5.0

I just drive at a steady 70mpg for a 100 mile trip. I often use cruise control to lock it in and kick back and relax. I wish cars had autopilot and drove themselves so I can take a nap.
Now, the highways in Texas are mostly very flat with few rolling hills. That greatly helps fuel mileage vs going up and down hills.
The rare times I saw 30mph avg is when there is a strong wind on my ***. Driving into the wind? At 70mph on same highways, maybe 24mpg avg

StuckInNYForever

With a 3.55 rear, I have had 23.5 in mixed 50/50 driving over a few tanks combined. I was going very, very easy on it. That should give me over 26 on highway. But it took tremendous, unsustainable self control to do that!

cjs06

Specs below. Got this going 70mph on my trip to VA.

clowe1965

Your specs bring up another point. Is the GT/CS/Boss front valence actually more aerodynamic? I think with the LS splitter it would be less due to the increased down force but the cs and the stock valences have almost the same configuration.

Bill_Texas

Thanks to everyone for the responses.

Falcon Fixer

2011 GT m6 with 3.31 rear gears.
Ceramic coated Stainless Works Long tube headers, hi flow cats, x-pipe and chambered mufflers.
Steeda CAI and aggressive tune to make it all run nice.

At 60 i get 26 to 29 mpg.

In October took it on a 550 mile road trip down I-95, doing an honest 70 mph I averaged 26.7 miles to the gallon.

The Ford numbers are for the 3.31 manual or the 3.15 automatic, I don't remember which one.

During the warmer weather I average 23 and in the cold 20.