I got 27 mpg driving from Texas to North Carolina last month. I don't do nearly that good around town, usually 20 to 22 mpg depending on how hard I get on it.

 

06 GT Manual, 17 city with a leadish foot, 26-29 highway @ 70 cruise. 91 octane, Bamachips tune.

 

I get 20 with mixed driving around town, on trips to NY and NC the best I've gotten is 28.8...... I don't take it real easy.

 

I find the trip computer to be a bit pessimistic. By the pump methodl, I'm averaging about 18mpg after 1700 miles, mostily highway at up to 80 mph cruising. I have a gt 5 speed vert with 18" wheels.

 

In the city about 16 mpg and on the freeway, the best I seen is 28 mpg. I could get better mileage in the city if I could just keep my foot off the gas.

 

My MPG has actually gotten better at a steady 13.3 MPG. This is all city traffic, stop light every block and 0-40 in just a few seconds. I don't even bother trying to take it easy anymore, seems I get a little better MPG driving it harder.

My best HWY was 23 but usually closer to 22.

Auto transmission, 91 torque tune and intake, stock gears.

 

05 GT auto. Everything is stock right now. I have averaged 20.79 mpg over a total of 20,757 miles. I keep track of my mileage with a spreadsheet (and yes, that IS a little obsessive). That probably breaks down to about 40% highway, 30% city, and 30% back roads with realtively light traffic.

 

LOL! I thought I was the only one! According to my spreadsheet I'm averaging 16.3. My car has 24k and is a stock 5spd. with the exception of flowmasters and a nasty air filter (wtf why don't the parts stores have 'em?)

There's a huge gap b/t city & highway. My highest observed was 26.5 which was on a trip where I was stuck going a steady 55. In town I only get about 13, but I have a real heavy foot! When I was driving my car to work every day I got about 18mpg cruising 60 miles/day at triple-digit speeds. Not so bad, but still not as good as the T/A (27mpg. regularly) IMO a 6-speed would greatly help this car. The T/A is just under 2000rpms at 85mph.

Hmmm I hope NC's finest isn't hanging around here!

 

Call me crazy but I figure the mileage on every tank of gas that I use. You can check my mods but around town 15 to 17 and highway 17 to 19.

 

Is it just me, or are the California cars averaging a few mpg less than people further east?

Bone stock 2006 GT Premium 'vert. / 6000 miles
I average 13.75 City and 22 Highway.
Best is 17.50 City (no fun at all) and 28.25 Highway (long road trip).

 

13 in heavy congestion, 17-20 around town, 25-28 highway. Highest I've ever seen is 28.8 for about 15 miles at about 70 when uh... drafting... behind an SUV that was in my way...

 

Thanks every one for the numbers. I get around 17 or so in my Wife's 2000 gt convert. 17 city and 27 highway is not bad at all for the new ones. I bet with a 6 speed it would be well over 30mpg's. I would not be buying for the mpg's but it is a small concern. By the way great site with lots of great info and people.

 

I'm trying to decide between stock gearing and the 3.55 option on an 07 Gt convertible. Can anyone comment on the mpg difference between the stock gears (3.31?) and the optional 3.55? Also is the difference in acceleration that noticeable? I believe the 3.31 would rev lower at any given speed which I would expect to improve mileage, I'm just wondering if it is negligible. Thanks.

 

05 GT with manual. All stock.

19 in the city and 24.5 highway going about 72-74 mph.

 

I know fuels are different for different regions... I know in Colorado, they're very similar to the fules in Cali... the emissions laws there are just as bad. The fuels are oxygenated pertty heavily, especially in the winter in CO... and your mileage goes down the toilet...
Now that I'm in Florida, and in a county that has very loose emissions laws... I would think that we'd have richer fuel here and get better mileage.. but I don't see a difference. I'm thinkin' it boils down to the fact that.... I can't keep my foot out of it.

 

Ok, you're crazy. But that means I am, too, 'cause I do the same thing.

 

the 355 will take less gas to get you moving but cost you more to keep moving. If most of your driving is in the city I would go for the 355 if more highway go with the 331. I would guess the mpg's with normal driving would be about 1 mpg. Good question. I hope some one chimes in that has done the switch.

 

My commute is part highway and part stop and go, around 15 miles each way. I've computed 17.7 as my best during a week and 15.8 as my worst. I do about 190 miles a week. Mine is a manual GT

 

17 " tires, JLT II SCT TUNE w/ 93 Octane--19 MPG's city---haven't really been on a long roadie, but i am thinking 24-25 highway

 

my 06 GT manual is doing 16.2 in 50/50 city/highway traffic. I got 1200miles on it. My co-worker who has exactly the same car (same color, same options - feels weird) he says he is doing 25mpg in 50/50 city/highway traffic.

I asked him if he is actually driving or getting towed most of the time, I have no idea how he can get that much, we both drive the same car in the same traffic. the other day I saw him on the road he was doing 35 in 45 zone, later the day he said "I saw you were flying" I said " Maaaan, I was just driving, but you were impeding the traffic"