I got an older coupe that for some reason is getting very poor mileage. I used to average out about 22-24 and now I get about 12 if that. I get about 230 miles on a 16 gallon tank. I have replaced the tires and done the alighnment. New spark plugs, new exhaust, new air filter, I cleaned out the air flow meter sensor and a frsh oil change with no sighns of engine sludge. My next step is replacing the fuel filter but I am running out of ideas. The car is turbocharged (oem) but no issues in that area. Any suggestions?

if you have after market rims, the would be weighing down your car. on my 745 i had 20s on it chrome and i was averaging around 10mpg when i took them off i was getting around 15-20mpg

I don't think replacing the fuel filter is going to increase gas mileage. I was going to say tune-up but it looks like you have done all that.

Sounds like you're not firing on all cyclinders. When you replaced the spark plugs did you test to make sure all plugs fired? Corroded spark plug wire maybe?

Is the car fuel injected? Does it have a distributor\points; Maybe the timing is off? Does the car have an ECM, have you checked the codes?

The car is stock with stock rims, the only thing thats aftermarket is some knock off cone air filter from autozone, the old intake setup was very bulky and didnt make much sense but it is installed properly. I put firehawk gt tires and there was a slight improvement. It is 4 inline turbocharged and fuel injected, fwd. I havent checked the spark plug wires but I will in the next few days. I was thinking it might be a bad fuel pressure regulator. I am going to order the fuel filter and fuel regulator sometime next week and see if that has an improvement. I really dont think its ignition related, when I removed the old ngk plugs they were in good shape. Map sensor maybe?

If you have a MAP sensor than you probably have an ECU? If you really enjoy working on your car I would suggest biting the bullet and shelling out $70-$200 to buy an OBD reader. The codes will tell you quickly what the problem is, plus maybe some other problems.

http://www.obd-codes.com/faq/obd-ii-code-reader-define.php

I wish, I am yet to find one for a saab

I can't take credit for this, another regular poster here just told me - "you should tell the guy to go to advanced auto..they hold your license and let you use the scan for free."

Hope that helps. Amazing what facts people know here.

I believe most Autozones will read the codes for free as well. Not sure that's going to help any though. If the problem is causing codes to be set, and it's been having the problem for a while, it should have illuminated the "Check Engine" light, or Saab's equivalent, by now.

cool, I will check out the autozone and see what they can do for me. So far there is no "check engine light" or "service light" (saabs have another light that goes on when its due for regular maintenance service)

Try changing the PCV valve (Cost about $6 bucks) and advance the timing 2 degrees

grunt Wrote:
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> cool, I will check out the autozone and see what
> they can do for me. So far there is no "check
> engine light" or "service light" (saabs have
> another light that goes on when its due for
> regular maintenance service)

Bad MAF may not trigger Check Engine light but still negatively affect your mpg (richer air/fuel mixture). See what codes they discover and go from there.

Bad turbo or, turbo leak or a stuffed catalytic converter may may be a suspect too, but it would negatively affect the performance as well, and you say it's not the case.

Even with the new cat-back exhaust(stock, stock, stock) the car is running just a little too rich so that might be the cause of that. When I first saw the white smoke, I was terrified that it might be the head gasket but lilely that wasnt the case. I think I need to replace a turbo gasket because it smokes up once in a while, especially after hard(er) driving and when the turbo is cooling down, I was thinking maybe the turbo oil supply line is bad so I will have that checked out as well. I am definetely leaning towards it being a bad maf or fuel pressure regulator, however the car runs very smooth. It takes about 30 seconds to warm up with my foot on the gas at 2000 rpms at the start otherwise it stalls out. After that it's 100% without misfire. Fortunately it's not my daily driver and it's more of a hobby . Thanks a lot for all the posts so far

besides being off-topic, this is the wrong board completely.


"the wisdom of the wise will perish, the intelligence of the intelligent will vanish."

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Edited 2 time(s). Last edit at 03/02/2012 09:54AM by Alias.

oh look, alias learned how to use some basic html. good for you alias!


"the wisdom of the wise will perish, the intelligence of the intelligent will vanish."

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Edited 2 time(s). Last edit at 03/02/2012 09:56AM by Alias.

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Edited 2 time(s). Last edit at 03/02/2012 09:56AM by Alias.

Gravis. Is Blue your favorite color?

Isn't it fun, being mentally ill?

Wow, this is fun!