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View Full Version : What happened to my gas mileage?


warrior
12-03-2009, 08:38 AM
I have an AEM DryFlow filter with a 3" neck that drops down into the wheel well. I never changed it for about 1.5 years.

I was losing about 120km (75m) per gas tank so I thought I should change that and wow.. that filter was caked on dirt! However, after changing the filter.. I noticed a big change but not what it used to be. Before I could squeeze out about 500km - 550km on the gas tank (312m - 343m) but now with the filter change.. I'm only getting about 470km (293m.)

I've also replaced my fuel filter just last month.. do I need to do an ECU reset in order to get my mileage back to where it was?? What could have gone wrong in other components with the shitty filter? o2 sensors or anything??
Huffer
12-03-2009, 09:15 AM
So you could average 500km on a tank? Or is that your "best" result? Dropping fuel economy could be a result of older spark plugs, clogged filters AND diluted gas.
warrior
12-03-2009, 09:24 AM
Since I've had my car.. i've always averaged about 500km.. i thought that wasn't too bad.. lol!

I should change my plugs too.. I think its been a year.. I'll try that see what happens
Grafton
12-03-2009, 01:36 PM
winter gas maybe?
Sarra
12-03-2009, 02:49 PM
Give it a few tanks to get back to where it was.

When I was tuning my WRX, I was getting 150-200 miles on a tank of gas. Normally I get 300-350 miles to a tank.
rudgers73
12-03-2009, 05:59 PM
winter gas maybe?

^^ that's what I was thinking too. Have you had your car for a winter? My average goes from about 26 mpg to 21 in the winter.
anothernord
12-03-2009, 07:18 PM
Winter gas has additives that reduce winter smog at the cost of efficiency. This could be your problem.
nipper
12-03-2009, 09:54 PM
It may be winter gas, may not. People think winter gas makes them drop thier MPG, when basically its just winter that does it.

Is it possible that your air flow sensor is not happy?
When was the last time the car had a tuneup?
how old is the o2 sensor?


nipper
warrior
12-04-2009, 02:59 PM
I don't think it's the winter gas.. I'll give it a couple gas tanks and I have no idea when the o2 sensors were replaced. I've had the car for 3 years and never replaced them.
nipper
12-04-2009, 03:10 PM
I don't think it's the winter gas.. I'll give it a couple gas tanks and I have no idea when the o2 sensors were replaced. I've had the car for 3 years and never replaced them.

How many miles are on the car?
Bdubs
12-04-2009, 10:10 PM
Check all your calipers! A seized or sticky one will kill your mileage.