LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Where oh where did my gas mileage go?

Thread Tools
 
Search this Thread
 
Old 04-05-2005, 08:23 AM
  #1  
Registered User
Thread Starter
 
cmbob67's Avatar
 
Join Date: Mar 2002
Location: Yo Momma's house!!!
Posts: 121
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..
cmbob67 is offline  
Old 04-05-2005, 08:40 AM
  #2  
Registered User
 
WS Sick's Avatar
 
Join Date: Dec 2003
Location: Oklahoma where trees are made of wood.
Posts: 2,725
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?
WS Sick is offline  
Old 04-05-2005, 12:26 PM
  #3  
Registered User
Thread Starter
 
cmbob67's Avatar
 
Join Date: Mar 2002
Location: Yo Momma's house!!!
Posts: 121
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!!!
cmbob67 is offline  
Old 04-05-2005, 12:28 PM
  #4  
Registered User
Thread Starter
 
cmbob67's Avatar
 
Join Date: Mar 2002
Location: Yo Momma's house!!!
Posts: 121
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!!!
cmbob67 is offline  
Old 04-05-2005, 12:53 PM
  #5  
Registered User
 
speed76demon's Avatar
 
Join Date: Mar 2003
Location: 1 hour south of springfield IL
Posts: 564
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
speed76demon is offline  
Old 04-05-2005, 01:04 PM
  #6  
Registered User
 
teke184's Avatar
 
Join Date: Sep 1998
Location: US 1 Mile Marker 52 in the Florida Keys
Posts: 8,321
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.
teke184 is offline  
Old 04-05-2005, 01:21 PM
  #7  
Registered User
 
1-bad-z28's Avatar
 
Join Date: Jan 2005
Location: Hopkinsville KY
Posts: 924
Re: OOps

sounds like it works good. You haven't said what the problem is
1-bad-z28 is offline  
Old 04-05-2005, 01:28 PM
  #8  
Registered User
 
Z95m6's Avatar
 
Join Date: Oct 2001
Location: newton, kansas, USA
Posts: 6,070
Re: OOps

Z95m6 is offline  
Old 04-05-2005, 01:33 PM
  #9  
Registered User
Thread Starter
 
cmbob67's Avatar
 
Join Date: Mar 2002
Location: Yo Momma's house!!!
Posts: 121
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.
cmbob67 is offline  
Old 04-05-2005, 01:38 PM
  #10  
Registered User
Thread Starter
 
cmbob67's Avatar
 
Join Date: Mar 2002
Location: Yo Momma's house!!!
Posts: 121
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; 04-05-2005 at 11:53 PM.
cmbob67 is offline  
Old 04-05-2005, 01:40 PM
  #11  
Registered User
 
V8 Slayer's Avatar
 
Join Date: Mar 2005
Location: Long Island, NY
Posts: 792
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)


Last edited by V8 Slayer; 04-05-2005 at 01:42 PM.
V8 Slayer is offline  
Old 04-05-2005, 01:59 PM
  #12  
Registered User
 
1-bad-z28's Avatar
 
Join Date: Jan 2005
Location: Hopkinsville KY
Posts: 924
Re: OOps

no problem
1-bad-z28 is offline  
Old 04-05-2005, 11:53 PM
  #13  
Administrator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,824
Re: OOps

Merging threads.......
Injuneer is offline  
Old 04-06-2005, 12:41 AM
  #14  
Registered User
 
speed76demon's Avatar
 
Join Date: Mar 2003
Location: 1 hour south of springfield IL
Posts: 564
Re: Where oh where did my gas mileage go?

Hell i've changed the 02's twice now. PCV can cause bad gas mileage I might have to check into that
speed76demon is offline  
Old 04-06-2005, 12:53 AM
  #15  
Registered User
 
SiDeWaYZz28's Avatar
 
Join Date: Jul 2003
Location: (SHOWING U MY TAILIGHTS)FaiRFieLD CaLiFoRNiA
Posts: 2,006
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
SiDeWaYZz28 is offline  


Quick Reply: Where oh where did my gas mileage go?



All times are GMT -5. The time now is 04:48 AM.