9mpg? That's pretty bad. I want to say that's close to racing mpg.

Your gauge being under 0 isn't a big deal, it just means you're not at sea level.

 

Nope I get 11 at autocrosses.

 

I get 9-10 in the dirt, but there's quite a bit of wheel spin...

 

Wow that's horrible. Even with aggresive driving, I get somewhere between 10-13 mpg.

 

9mpg and granny shifting? I'd check to see that you're not pouring fuel directly onto the ground...

 

Wait, at WOT the needle rises to 0?

where is it when the car is off?

 

not WOT, just about higher then average acceleration My guess about 30-35% pedal down

Under my normal, I usually keep it at around 20-25% Which I personally think isnt that much.

When the car's off its at 0, When its idling its -0.5 I think. Which is normal I believe.

 

Yes being at 0 means you're not boosting or very close to it since the gage typically will be slightly different than the pressure the ecu sees. Most people tend to trust the ecu over a gage. If you are getting 9mpg with the driving that you described in your first post then you have some sort of problem with the car. It would be a good time to see a shop about getting it figured out. 9 mpg is awful. With the way you say you are driving you should be seeing more than 20mpg. The sti isn't good for gas mileage thats for sure but it should be around 20 or slightly less or a bit more depending on driving.

 

Yeah. I would like to get 20mpg. That would be very dream lol.

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Not sure how the Gd 07 changed as in gas mileage, i do know in the 08+ if you reset the trip meter it also resets the mpg back to zero. Im constantly reseting mine when i go from 19mpg to under 16 in the cold where i sometimes granny it back home after work.

 

There's no actual mpg counter till 08+. I had to manually go online and punch in my miles driven and fuel comsumed.

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How many miles per tank are you getting?

 

About 180

>
Oct 2011, haven't touched my maf

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When was the last time the air filter was changed? Ever have the maf cleaned? You may also need to do a boost leak test.

 

Your car has no where near a 20 gal tank, In my 06 I was lucky to get 13 gal into it from empty so your getting more like 14mpg. Still terrible but no where near as alarming.

+1 for checking your engine air filter and clean your MAF.

 

Well I didn't do the math exactly I was out. STI tank is 15Gal, It various from 160-180, 180 being my best. I just looked at the dash and it just over 80miles and i'm half way done the tank. So its about 9-10.

 

yeah. That's what I've been doing. I'm half way done. I'll report back with another set of numbers for this tank. But whatever it is. I know its going to be low double digits..

 

Wirelessly posted

You should get the box wired in like another member on here. 500+ miles per tank! :lol:

 

I average from 250 - 300. Depending on the weight of my right foot.

 

So, just to be sure, you divided the total miles driven (trip A mildeage) for that tank divided by the gallons filled at the gas station, right?

Stock-sized rim/tires?

I wouldn't discount a fuel leak.

 

corrected. Thats how I've been getting my MPG,

Not sure what stock size tires are. not really in the mood to search but I'm currently running stock size rims with 235/45R17

 

Don't trust the fuel gauge on the dash, it's terribly inaccurate. Fill it up full, reset the odometer, and then drive. Then fill it up full, divide the miles driven by the amount of gallons put in. That's your gas mileage. In town, I get around 16-17mpg and highway I get like 21-22 mpg in my Stage 2 06 STi.

 

FYI winter gas is a different spec than rest of the year. This also has an effect on your gas mileage. refineries have to make changes to how the gas is refined and certain processes make the gas less mileage friendly.

Summer time I'm averaging 20-21 mpg and this winter it's been 18+/- mpg. Stage 2

 

Yeah I put that into account. But I shouldn't be getting "racing" MPG when i'm tapping the throttle just enough not to stall..

 

Just cleaned my maf senor, it was black. So I think that might be my issue. I'll report back and see what happens.

(IAT sensor didn't pic of the actual maf.)

 

I need to clean my sensor as well. Been neglecting the intake a while

 

You didn't touch/scrub it did you?

 

Just sprayed and air dried.

 

I would reset the ecu too.

 

The ecu should learn the new fuel trims anyway, and if this doesn't help, the fuel trims may help someone looking at the car to find out what is wrong. So I personally wouldn't reset the ecu.

 

... or, reset the ecu and see if it comes back. I personally don't see anything wrong with a quick reset after cleaning the MAF.