15 or Less MPG? Something Wrong?

[Sparty92]

I get about 17-18 with mostly city driving. On the highway, if I keep it at 65-70, I saw about 24.5. I have 3.73 gears and man. trans. I have 5,100 miles now.

I also have issues with my "oil life indicator," which told me I was at 10% oil life with just 4,700 miles. Apparently there is a TSB for this problem...and they will reprogram the PCM. Maybe...this will update the Avg. MPG too? I mean, if my 2007 with 3.55s at 70 mph could pull 30mpg, and my 2011 with 3.73s at 70 pulls the same RPM (2,200)...why can't I pull similar mpg numbers?

 

[JKidd]

I've been mildly concerned as well about my gas mileage (2011 GT, 6MT, Brembo and 3.73's).

I've been getting 16-18 mpg. She's just clearing 1800 miles and I was pretty gentle the first 1000. I'm starting to get on it more now and I hope that loosens things up a bit (plus its wicked fun).

Hell, my '92 5.0L LX Convertible with all its pushrods gets 20 mpg.

Driving the same routes (80% highway, 20% city), my 2001 BMW was getting 25-26 mpg (got 33 mpg on a trip to Atlanta last year). I was hoping for at least 22 mpg with the Mustang. Maybe she'll get there...glad to see I'm not the only one with low gas mileage.

 

[JKidd]

I mean, if my 2007 with 3.55s at 70 mph could pull 30mpg, and my 2011 with 3.73s at 70 pulls the same RPM (2,200)...why can't I pull similar mpg numbers?

EXACTLY!!!

 

[642mx]

My wife drives the car more than I do... she gets 20-22 mpg (mix of highway and city). I can't seem to get above 16 mpg when I'm driving it...

 

[SkyRender]

Make sure you reset the MPG meter at every fill up.

FWIW, I average 22 MPG in a mix of city and highway driving in my automatic 5.0.

 

[Ronin38]

I was on a drive last week, and Reset the Avg. MPG just after I got on a local 4-lane route. Set the Cruise to 62 mph (posted 55 area), and after 20 min. I was reading 28 mpg! It held that number for quite a while, too.

Not bad for 353 rwhp!

 

[94GTLaserRC]

Iwhy can't I pull similar mpg numbers?

80 more HP

RC

 

[Sparty92]

Make sure you reset the MPG meter at every fill up.

FWIW, I average 22 MPG in a mix of city and highway driving in my automatic 5.0.

I do reset the mpg meter. In fact, that's the nerdy sort of thing I've done after every fill up for the past 10 or so years.

I've decided to just change the display to the hilarious "bar graph" for efficiency monitoring, and once in awhile, poke the "avg. mpg" button to see how I'm doing. Less stress that way.

 

['13_ImpactBlue_GT]

I do reset the mpg meter. In fact, that's the nerdy sort of thing I've done after every fill up for the past 10 or so years.

I've decided to just change the display to the hilarious "bar graph" for efficiency monitoring, and once in awhile, poke the "avg. mpg" button to see how I'm doing. Less stress that way.

Bar graph FTL

 

[SkyRender]

Bar graph FTL

I actually kind of like the bar graph, though I notice it is usually completely full (decelerating) or completely empty (accelerating even moderate amounts).

 

[Sparty92]

I actually kind of like the bar graph, though I notice it is usually completely full (decelerating) or completely empty (accelerating even moderate amounts).

It's totally flat when you're breathing on the accelerator.

 

[JayhawkGT]

Lots of variables here but I think as has been pointed out GEARS are probably the biggest factor.

Ford on the window sticker states the car in city driving has a range of 14 mpg up to 20 mpg. The city driving in bold is 17 mpg which is right where you seem to be. Highway has a range of 21 mpg up to 31 mpg...

 

[thelastsumurai]

On my stock Automatic w/315 gears 11 GT I get about 22.3 mpg local driving (Ocala, FL). My girlfriend got 23.9 when she went up top Ga. to see her mom and pop. I think it depends greatly on how hard you are on the gas peddle I have never gotten lower than 20.2 mpg on 9,000 of use.

 

[Coyote5.0]

I have found that ethanol in the gas (and maybe the octane rating) has a big effect on this car.

My first two tanks on mine, I was being cheap and used 89 octane (for some reason, one station sells mid-grade for the same price as regular) with 10% ethanol and got 23.3 on the computer (23.9 on a calculator). Last weekend, I sprung for 91 octane with no ethanol. After 150 miles of the same type of driving, the computer is showing 27.3.

 

[captbill51]

updated mileage

I have 8000 miles now after a trip to Florida from New England. I get a constant 22-24 on the highway cruising at 70 mph/2200rpm with 3.55 gears...sweet.
When I drive with "sport mode" and am having fun about 17mpg is the norm.

 

[Sparty92]

I don't think we can get ethanol-free gasoline in Michigan. It's all 10%.