Where oh where did my gas mileage go?
Thread Starter
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Joined: Mar 2002
Posts: 121
From: Yo Momma's house!!!
Where oh where did my gas mileage GO?
Normally I can see how my car is on gas by driving out of town around 250 miles striaght (all highway miles). I figure that would be a good way to test how many miles I can get from a full tank of gas. Well when i first bought the car with 55'000 miles on it I was getting 330 miles to the tank. This past weekend (With 100'000 miles on it) I took a trip and got 234 miles to the tank. That F^$#*in crazy. I somehow lost about 100 miles. I don't have any funny smells coming from the Catilitic converter, but i did remove my air pump. What could be some other problems that would contribute to this problem?? Any info would be helpfull.. 
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Joined: Dec 2003
Posts: 2,724
From: Oklahoma where trees are made of wood.
Re: Where oh where did my gas mileage GO?
How long has it been since a tune-up? air and fuel filters will really effect it. as will oil consumption. Do youhave the same size tires and wheels as before?
Thread Starter
Registered User
Joined: Mar 2002
Posts: 121
From: Yo Momma's house!!!
OOps
Same size tires as stock. Plugs and wires were changed at 75'000 miles. I made my own 3 1/2" CAI with a brand new K&N on it. My Performance feels pretty good. I'm thinkin that the cat could be in the beginning stages of becoming clogged up, causing the engine to work harder. I'm not throwing any codes either. Weird stuff. Please Help!!! 
Thread Starter
Registered User
Joined: Mar 2002
Posts: 121
From: Yo Momma's house!!!
Re: Where oh where did my gas mileage GO?
Same size tires as stock. Plugs and wires were changed at 75'000 miles. I made my own 3 1/2" CAI with a brand new K&N on it. My Performance feels pretty good. I'm thinkin that the cat could be in the beginning stages of becoming clogged up, causing the engine to work harder. I'm not throwing any codes either. Weird stuff. Please Help!!!
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Joined: Mar 2003
Posts: 564
From: 1 hour south of springfield IL
Re: Where oh where did my gas mileage GO?
my gas mileage sucks too and I have no cat. Changed all plugs, wires, fuel filter, have a new CAI. Also have new opti and fuel pump. Car seems to run strong as hell but I get ****ty gas mileage go figure
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Joined: Sep 1998
Posts: 8,319
From: US 1 Mile Marker 52 in the Florida Keys
Re: Where oh where did my gas mileage GO?
when was the last time you changed your 02 sensors?
are you sure it was the same amount and type of driving?
remember going from 55mph to 65mph doubles the wind resistence on the car....it's a squared function. so that can have a profound affect. as could weight in the car and just plain age on the engine.
are you sure it was the same amount and type of driving?
remember going from 55mph to 65mph doubles the wind resistence on the car....it's a squared function. so that can have a profound affect. as could weight in the car and just plain age on the engine.
Thread Starter
Registered User
Joined: Mar 2002
Posts: 121
From: Yo Momma's house!!!
Re: Where oh where did my gas mileage GO?
As Long as I've owned it the O2 sensors haven't been changed, So that could be it. I was cruising with the windows open and AC off the whole way. My average speed was about 75 to 80 mph the intire trip. I don't think my continuious 75mph would cause my car to lose 100 miles per tank. Thanks for the Info!!! Keep the ideas commin ya'll.
Thread Starter
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Joined: Mar 2002
Posts: 121
From: Yo Momma's house!!!
Re: OOps
Sorry Ya'll. I accedently posted a new post when I was tryin to reply to another thread. Sorry about the screw up. The original post is (Where oh where did my gas mileage GO?) My MPG sucks ***. I'm trying to get ideas on whats wrong with it. Thanks !!!!
Last edited by Injuneer; Apr 5, 2005 at 11:53 PM.
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Joined: Mar 2005
Posts: 792
From: Long Island, NY
Re: Where oh where did my gas mileage GO?
1.Check tire pressure (30-35 PSI is good)
2.Run a bottle of fuel system cleaner (STP,Techron etc...)
3.Average engine temp? (180-220 is normal,anything below will waste gas)
4.Bad O2 Sensors? (Will NOT always throw a code,change them anyway)
5.Try a different gas station and or grade of gas.
6.Check Cat (Possibly clogged?)
7.STOP FLOORING IT!
8.Mega tuneup (All fluids and filters,plugs/wires and PCV Valve)
2.Run a bottle of fuel system cleaner (STP,Techron etc...)
3.Average engine temp? (180-220 is normal,anything below will waste gas)
4.Bad O2 Sensors? (Will NOT always throw a code,change them anyway)
5.Try a different gas station and or grade of gas.
6.Check Cat (Possibly clogged?)
7.STOP FLOORING IT!
8.Mega tuneup (All fluids and filters,plugs/wires and PCV Valve)
Last edited by V8 Slayer; Apr 5, 2005 at 01:42 PM.
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Joined: Jul 2003
Posts: 2,006
From: (SHOWING U MY TAILIGHTS)FaiRFieLD CaLiFoRNiA
Re: Where oh where did my gas mileage go?
its porbally your descreened maf that screws everything up TRUST ME or it may be your o2s but im pretty shure its your maf