I get 9-10 in the city and about 18 on the highway. I could never get more than 20 on the highway... eh

 

You guys use regular oil changes or synthetic oil??

 

same here... about 250miles with a full tank... -_-

 

i driven from sac to irvine/rancho santa margarita with about 2 gallons left in the tank... that's about 430 miles.... kept the speedo above 75 mph for most of the trip.

in town, i can get 325-350.... i do regular oil changes and only use 91 octane (switched to shell.... i tend to get slightly better mileage with shell than chevron)

so yeah you may need a tune up...

 

nonono dont switch to 89 stay at 93 93 burns slower.. your friend is wrong hate to say. stay with 93 89 will only make it worse

 

Everyone i speak to says 93 burns slower, my friend has a g35 sedan and he even says 93 burns slower then 89 so ill stick with that. But i dont know what else could be the problem i got a brand new oil change i put in the fuel injector cleaner and ill see how that goes. Its official though i only got 101 Miles from a full tank of gas to half tank. Thats only 10 MPG... This is crazy i understand its a sports car and i knew what i was gettin myself into but jeeze thats bad.. i thought i was goin to be at like 15MPG at least... and right now gas is low but wats gunna happen we it goes back up 2 4 dollars.. im still under warranty i guess im gunna bring it in and tell them to check it out...

 

Just curious, how many gallons of gas did it take to fill it back up after the half tank?

Best way to check milage is to fill up the tank till the pump shuts off (preferrably filling it up slowly to avoid sloshing). Then reset the trip odo. Drive a while (most of a tank). Refill (preferrably at the same pump for consistency) the same way as before. Then divide the miles on the trip odo by the gallons it took to fill the tank. (FYI most cell phones have calculators so this is pretty easy to do before you even pull away from the pump).

Ohh, then reset the trip odometer before you leave the station and do it again the next time. Do it several times because things vary it. New tires get worse milage for a bit, idle to warming up a car, even cold/hot weather can vary it back and forth. Personally I check the milage every time I fill my car. (But my wife thinks I'm crazy for it.)

 

welcome to my world i get 12-14mpg

 

I get 14-16mpg with the mods.

 

Yes actually my tires are brand new... i might need to check the tire pressure... thanks alot and ill calculate it when i fill up tomorrow ill let you know..

 

No they're not.. Don't mis-inform yourself. Premium is RECOMMENDED... Do you really think that the mid-life crisis 40-50 year old lady will pump 91 in her Z or G? Don't think so..

I've been running on 87 for a while- Only to prove a point to myself and my friends about this car.. The most I've got was 380 miles on a full tank of 87 octane.

 

Here's another data point. I have the 6MT sedan, and I average about 19mpg. I divide miles driven over gallons filled at every single fillup and keep it in a spreadsheet; yes, I'm ****

The best I ever do is almost purely highway driving, which is 28-29 mpg
The worst is all city driving, which is 14-15 mpg.

These aren't the most fuel efficient cars in the world, but very powerful and fun to drive.

 

so im just updating you guys on the correct gas millage.. not as bad as i thought but still pretty bad... Its exactly 12.5 MPG.. here are the pics... Also my tires all say they have 32 PSI but on the tires it says max 51.. should i put more air to 44? Everything else is clean new airfilter oil change.. i guess im just goin to have to live with it lol.. in the spring i plan on gettin a intake maybe that will help if i dont floor it all the time lol

 

hmmm... I get 24~26mpg mixed driving 80%city/20% freeway.. have gotten 30+mpg on the freeway..
try setting your tire air pressure to 36psi (not that it'll make to big of a difference)
Tires could make a big difference too.. since you have the coupe, you probably have bigger and stickier tires (heavier?) than my sedan. That would increase rolling resistance..
If your car is in tune, it's very interesting that you are only getting 12.5mpg.. hmmm...
what kind of oil do you use? What brand of gas do you use?
Drop in a bottle of techcron fuel system cleaner when you get a chance...
even with a 15% increase.. you'll be hitting ~15 mpg!!

 

An intake won't help you save fuel, and overinflating the tires won't help very much either. Run the stock pressures, it's a good mix of comfort and performance.

12.5 mpg is low. There's something strange going on.

Do you take a lot of short trips and let the engine cool down in between? When the catalytic converter is cold, the ECU dumps a lot of unburned gas into it to get it up to temperature quickly, which results in horrible mileage for the first couple miles you drive. I don't think I get much over 10mpg with a cold cat either.

Maybe you have a bad O2 sensor which is causing your engine to run very rich?

Another possibility is that there's some sort of high friction loss somewhere in your powertrain, like a brake grabbing. After a drive, check to see if you have any unusually hot spots on the car, like a wheel or the driveshaft tunnel.