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Why do my MPG's suck so badly?

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Old 05-12-2010, 11:58 PM
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stangit9090
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Default Why do my MPG's suck so badly?

I have full exhaust, 3.73's, an sct tune for 93, and a K&N filter with the snorkel removed. I get such ****ty MPG's. I can almost watch the gauge go down when I get on it.

I have all of the correct o2 extenders and MIL eliminators, no CEL's what so ever.

I'm planning on getting a tune after I get a tb/plenum. I know this will help some.

Did the headers and new h pipe make them go down? The computer compensating for something? I have no header/exhaust leaks.

IDK.
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Old 05-13-2010, 12:02 AM
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H0SS302
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I think your tune is really rich. Iv noticed a substantial amount of people who have SCT tuners get terrible gas mileage while using a tune generated from the SCT factory. I have more mods than you and I get about 26 mpg highway with 4.10s. Im 99% sure your tune is just rich.

Last edited by H0SS302; 05-13-2010 at 12:05 AM.
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Old 05-13-2010, 12:03 AM
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99GTvert
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It might be time to perform some regular maintenance.


Fuel filter, spark plugs, clean/change air filter, etc. Also, check your tire pressures and remove any extra crap that's in the trunk or back seat area.

+1 to H0ssyboy. Your tune might just be very rich.
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Old 05-13-2010, 12:08 AM
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stangit9090
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Originally Posted by 99GTvert
It might be time to perform some regular maintenance.


Fuel filter, spark plugs, clean/change air filter, etc. Also, check your tire pressures and remove any extra crap that's in the trunk or back seat area.

+1 to H0ssyboy. Your tune might just be very rich.
lol my car has 20k on it.

I change the mobile 1 synthetic every 2.5k, and wash the K&N every oil change...

it got amazing mpg's before i did **** to it.

I checked the plugs and they're mint and gapped correctly. Got a new fuel filter 5k ago.

only think in the car is my *** and my bat. yes ghetto.
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Old 05-13-2010, 12:17 AM
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H0SS302
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Its your tune... SCT sucks *****. lol Delta Force tuning or bust.
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Old 05-13-2010, 12:17 AM
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SVTeeshirt
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1. your car has a snorkel? i thought they belonged on jeeps?
2. why are you wasting your money on synthetic then changing it even before a dyno oil would need changed? Im all for maintaining a car but there is such thing as overkill.
3.I think hoss is spot on, same thing happened to my buddys 99 GT the SCT canned tuned was waaaay to rich, they don't wanna be responsible for blowing up anyones car.
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Old 05-13-2010, 12:20 AM
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stangit9090
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Originally Posted by SVTeeshirt
1. your car has a snorkel? i thought they belonged on jeeps?
2. why are you wasting your money on synthetic then changing it even before a dyno oil would need changed? Im all for maintaining a car but there is such thing as overkill.
3.I think hoss is spot on, same thing happened to my buddys 99 GT the SCT canned tuned was waaaay to rich, they don't wanna be responsible for blowing up anyones car.
tomato/tamoto.

and it's no big deal to change oil, i like doing it.
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Old 05-13-2010, 12:50 AM
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H0SS302
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Originally Posted by stangit9090
tomato/tamoto.

and it's no big deal to change oil, i like doing it.
Yea its no big deal, but your throwing your money away. The ONLY point to synthetic oil is the longevity of it.
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Old 05-13-2010, 12:58 AM
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SVTeeshirt
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Originally Posted by H0SS302
Yea its no big deal, but your throwing your money away. The ONLY point to synthetic oil is the longevity of it.
bingo! hot dog we have a weiner.
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Old 05-13-2010, 02:17 AM
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teej281
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Get a wideband o2 sensor and gauge and clue us in on your findings...i think you might be running very rich as well.
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