I got 12 on this tank of gas for z. It only has flowmaster exhaust so...

 

Lay off the throttle?
How long since a good tuneup?
Exhaust leak causing it to run rich?
Tires in good shape with correct air pressure?

My bolt-on '95 A4 runs about 16mpg ... mostly highway and a little 'round town ... totally babying it.

My stock '97 T/A M6 got about 22mpg on its last tank ... same highway/around town combination ... and in dire need of a tune up (taking care of that right now).

 

In the thread you posted immediately before this one, you indicated your Z is slower than your 2002 Nissan Frontier. That would appear to indicate there is something seriously wrong with your Z.... and an engine that is way down on power is not going to get good gas mileage. Time for some serious diagnostic work.

 

I get 21 combination driving in a stock 97Z M6 with a flowmaster muffler/stock pipes. my 93Z A4 is all stock, and gets 20 in combination driving, (50/50 highway /town) Both cars are over 100K miles with just regular maintenance. You got a problem.

 

I wasn't saying it was faster, it just felt zippier...but I do need to get some checkups done on it, which is why I took it to the shop today!

 

Then what does "zippier" mean?

 

It felt like it was less work to get it up to speed than my z. Since it's an automatic I guess I didn't have to push in the clutch for everything as well.

or

from Merriam-Webster: : full of zip: as a: very quick or speedy <a zippy sports car> b: strikingly fresh, lively, or appealing in style <zippy clothes>

 

you need to do a complete tune up. Fuel filter, air filter, plugs and wires, o2's, change all fluids, clean maf & tb, I could go on and on.
Tell the shop it gets pis poor mpg's and they SHOULD know what to do.

 

Will do

 

If there are no codes, why change the o2s on a tune-up? I'm asking because I think I need to replace my front o2s, but just can't justify the expense right now if there are no codes.

 

Well clutch and flywheel resurface...$950! Ya me!

 

Need alot more info before anyone can help you. First did you just get the car or do you have a baseline of the fuel economy. Next how many miles, and if so when was your last tuneup. Next any mods, and if so what are they. Any codes or is the check engine lite on? Does it run smoothly and have power?
Check your air filter, do a tuneup of plugs and wires if it has not been done, replace/ clean your airfilter, change your fuel filter, check your tire pressure.
Add a quality fuel injector cleaner to your gas when you get under a half tank.
Change o2 sensors if have not been done in a while. These steps should get you back to a acceptable mileage per gallon, but if there is a problem that will need to be addressed first.

hth

andy schuck

 

Well just got my car back from the shop and now she shifts like a dream. No wobble and no problems! 905 bucks, but it was worth it. Now I need a tuneup...

 

just got 19.6 with combo driving. head cam car M6