trek757

I have an 06 GT auto. I modded it right after I got it so don't know about stock mileage. Now I have a Brenspeed 93 octane tune, C&L CAI, Mac axlebacks and I average 16 city and 24.5 hwy. Which I am happy with. Oh yeah, I use Mobile 1 oil also. I think that and the tune actually help mileage.

thefrantic1

yea just thinking about it, my mpg didnt change much til my gear change which i expected. jmart69x hwy mpg seems low.

SD05GT

Just a quick question; are you doing this mathmateically by hand or is this what your computer is telling you? If it's your computer; zero your mpg, odometer, average speed, etc etc. I think you might have a low average over the course of several months and not just one tank of gas?

rpatyna

All of you seem to have low gas mileage. My car is a modifed as an N/A car can get and I still get 30 MPG at 60 miles per hour.
Even a mild tune will increase mileage.
Rob

GT Bob

You hit the nail on the head. Your going to find the closer to 55 you drive, the higher the mileage. I can pull 30 mpg all day if I stay under 60. Go to 65 and it drops off to 26 and at 79 to 80, it's down to about 22.

And yes, you will find a mpg or 2 from a CAI and tune combo.

Mishri

I got about 15mpg on the highway.. I had a horrible head wind.. the return trip i got like 30mpg doing 80.

Fullsayl

FWIW - I think you might have forgot to reset your computer. Try disco'ing the battery overnight and give it another shot by hand from scratch. If you are still getting < 20MPG on the highway, seek assistance 'cause something is wrong...or you are doing 100+ (which is only kinda wrong depending on location, weather, etc.)

~Matt

capitalautomall

i have a 08 gt 5 speed.
just got it 4 month ago. i have about 5k miles on it. on a 16 gal tank i can only run about 150 miles. it show me that i have 12.8-14 mpg. after i install the cai and tune . i run about 165 max with one tank. but i think that is still really low. btw i do about 80% city/20 % highway

Derf00

Stop and go or short trips will KILL your gas mileage on a GT. I am learning this. I've had mine for a bout two months 2,200 miles on it so far. MPG has improved over the first month to where I average 18.5-19mpg with a combined of about 50/50. If I do more city driving then I get 15-17mpg, more highway I've gotten up to 21.5 mpg. That's an average per TANK not just reseting the meter whenever I switch driving types.

doogyhap

I got around 24 MPG on a 300 mile trip a few weeks ago on my 08 with a KB supercharger. Of course I drove 60 MPH. AlsoI was using 93 octane.