I got about ~25mpg for about 50-60 city miles, then it went down b/c i couldn't take it any more. So for the past ~ 100 miles in the city, i'm at 23.4MPG. I guess that's my record.

 

My car must be different from everyone elses b/c I get about 26 mpg mix city/hwy. I get about 31 mpg strictly hwy. The LOWEST I got was about 19 mpg but that was intentional. Oh, I also noticed so far Shell gasoline is the best for mpg.

 

if you got a pic phone i can send you a pic message to verify my gas mileage. just reset the cars ecu like i recomended adn you should be fine. your car is most likely running off of the dealerships driving habbits. Its more then likely they were flooring it every chance they got. I had the Same problem and SGP told me to unplug the battery for a couple of hours adn I was up to at leaat 24 miles city and 30-31 highqY

 

Doesn't resetting the reading for mpg/avg mph do that? I don't understand unplugging the battery.

 

No all that does re avg your gas mileage but the car may be running rich on gas because it thinks your foot is made of led, instead that may not always be the case.
Unplugging the battery for about 5 hours is going to allow the computer to re learn everything about the car, as your driving style and all of your cars sensors and components. by your car using so much fuel it thinks your are richard petty instead of the avg joe.
By adding a pop charger will also increase your gas mileage because the more air is forced into the enjen. but in about 5 day or so it will taylor down and your gas become rich because the car has more air than the ecu know so the ecu add more gas to compensate for the air it is has. its sorta like the car thiks its going faster then it is due to the air so the car panics and dumps more fuel.
When z owners add parts like pop charger, plenum spacer, exhaust, headers, cats, test pipes and all that stuff they must get a tune from a speed shop like sgp that will tune the car with e-manage ultimate adn a reflash because if you didnt your gas mileage would scuk. Getting yor car reflashed and tuned with e-manage simpley reprograms your computer to accept your custom parts with added air flow and allows the z to use the correct air flow adn gas for your parts wich will incrase your gas mileage pretty much back to the normal stock 24 city 29-32 hwy. using theese parts will increse your total horse power by adding air and you dont have to sacrafice gas mileage as long as you get it tuned.
TIP: Go to auto zone and get a product called SEAFOME adn put the solution into your gas tank, about 1/4 tank. this product will clear all the carbon build up that you may have in your fuel lines from you car sitting at the dealer and other toxins from daily drivin. you will notice the immidate differance in your exhaust sound and your throttle response so try this and get back to me and let me know how it goes.
Dont let other z owners convince you that gas mileage isnt important because it is. In short unlug your battery,fo 5 hours min, go get the seafom from an aut parts dealer, and when you start adding parts get it tuned with e manage ultimate adn a reflash. And have some one check your spark plugs adn i pormise you will see at least 29mg highway and 23 city

 

Never mind I don't care.

 

i used to get 21-22 mpg city, and 30-31 on the highway. you need to re-examine how you drive if you only get low teens mpg. thats really bad.

 

steady 24 mpg with my daily city driving

 

wow...alright...I got to try the batter disconnect then this weekend! Not sure about the seafoam...I never was into adding into my fuel tank other than fuel.

 

my Z averaged 29mpg cruising at 65mph and only 21 at 90.

 

i just drove from florida to missouri and i averaged 28mpg... cruise control set to 77 and 93 pump gas (only mods k&n intake and full exhaust system) ... i found that using cruise control on hwys makes a huuuge difference.

 

Same here! I have 28,000 miles on my car- still on original rear tires (front were replaced under the noise replacement warranty ) - and original front brake pads. If either tires or brakes wear fast - usually a sign of fast starting and/or fast stopping an unusual amount. I get 27 mpg on a road trip.

 

Those who dont like reposts shouldnt open them!

 

I get like 17 in city driving and like 20 on the highway and I only have 500miles on it. So disconnecting the battery will fix that?

 

I just filled up my Z for the first time since I bought it (it has about 1,000 miles on it now; it had around 750 on the clock when I bought it Wednesday). Calculated mileage was 22 mpg with about a 50/50 mixture of city and highway/Interstate (55-75 mph). And that also includes a few brief runs to 100+ mph.

I'll be making a lot of long highway/Interstate trips in the next 12 months, so it will be interesting to see what kind of fuel economy my car gets under those conditions and as it gets broken in. And I plan to put in Mobil 1 at its first oil change, and possibly synthetic transmission/differential lubricants as well.

 

DAM i gotta try the battery disconnection. Even with very light driving, I see 17 as my highest for highway.

 

I've got an auto 06' with 1600 miles on her. With all city driving on this tank I filled up and calculated my mpg to be as the gauge read 17.4 mpg, avg mph was 23. I also had reset the timer and I ran 10+ hours on 12.5 gal of fuel, calculating fuel per hour I'm using 1.25 gph. I think it's due to too much idle time!

 

I get, normally, 21-22mpg according to the gauge. However, I tend to, most of the time, have a lead foot, so my mpg reads 19.0 most of the time.

 

if anybody has any additional questions feel free to pm me

 

25 is my usual average but even after heavy driving I'm usually averaging high teens to low 20s. Measure it not with the gauge but by emptying the tank and filling it back up and then seeing how many miles you can get out of a tank and divide by the number of gallons you put in.