South Central Region Board for the states of Texas, Oklahoma, and Louisana.

Remember when I said my mileage was terrible?

Thread Tools
 
Search this Thread
 
Old 01-25-2008, 04:21 PM
  #1  
TGO Supporter

Thread Starter
 
Sonar_un's Avatar
 
Join Date: Nov 2000
Location: Houston, TX
Posts: 2,201
Likes: 0
Received 0 Likes on 0 Posts
Car: '86 T/A
Engine: 350/LT1 Intake
Transmission: 700R4 - Built
Axle/Gears: 4th gen 3.42
Remember when I said my mileage was terrible?

My car is strange, it does this all the time. On average my car gets about 190 or so miles to the tank. I am usually pretty happy if I manage to hit 200 miles. Well, the last tank I managed to get 240 miles out of it. I scored a perfect 20MPG after I ran the calculations.

I watch my mileage like a hawk and the car does this fairly often. I will go a couple months averaging 190 miles, and then out of nowhere I get another 50 miles out of the tank and I will usually be able to fill up once or twice more with this higher mileage and then it goes back down to 190 miles.

My driving habits never change either, you can damn near set a clock to it. 99% highway miles, no major speeding (maybe like 5-10mph over) and the same route every single day.

I wish I knew what the hell happened to the car to get me higher mileage.. if I knew, I would positively do more of it.
Old 01-26-2008, 08:20 AM
  #2  
esc
Moderator

iTrader: (6)
 
esc's Avatar
 
Join Date: Nov 2002
Location: North of Houston
Posts: 2,004
Likes: 0
Received 8 Likes on 6 Posts
Car: '82 Camaro 11.7@121
Engine: 377
Transmission: 400
Axle/Gears: Dana 44 / 3.31:1
Re: Remember when I said my mileage was terrible?

Could it be the cold weather? If you were normally running rich the denser air might give you a better mixture and result in better mileage.
Old 01-26-2008, 10:48 AM
  #3  
Supreme Member

iTrader: (2)
 
Reid Fleming's Avatar
 
Join Date: Sep 2006
Location: Houston, TX
Posts: 2,118
Likes: 0
Received 14 Likes on 11 Posts
Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: Remember when I said my mileage was terrible?

Originally Posted by Sonar_un
Well, the last tank I managed to get 240 miles out of it. I scored a perfect 20MPG after I ran the calculations.

Sounds like you've got the 12 gallon tank deal like I do. Could be that you haven't been using the A/C as much this last little while. Less traffic? Who knows.
Old 01-26-2008, 10:53 AM
  #4  
Senior Member
iTrader: (1)
 
ryan91rs's Avatar
 
Join Date: Sep 2007
Location: New Philadelphia/ Canton OH
Posts: 914
Likes: 0
Received 1 Like on 1 Post
Car: 1991 RS, 84 El Camino conquista RIP
Engine: 5.0 (for now)
Transmission: 4L60
Axle/Gears: 2.xx torsen limited slip & 3.42 ope
Re: Remember when I said my mileage was terrible?

colder day + defroster = AC running and worse AVG MI. just a thought
Old 01-27-2008, 12:37 AM
  #5  
TGO Supporter

Thread Starter
 
Sonar_un's Avatar
 
Join Date: Nov 2000
Location: Houston, TX
Posts: 2,201
Likes: 0
Received 0 Likes on 0 Posts
Car: '86 T/A
Engine: 350/LT1 Intake
Transmission: 700R4 - Built
Axle/Gears: 4th gen 3.42
Re: Remember when I said my mileage was terrible?

I don't have A/C.. and secondly it happens in the summer months as well as winter months. This has been going on and off now for a couple of years.
Old 01-27-2008, 12:43 AM
  #6  
Supreme Member

iTrader: (1)
 
DENN_SHAH's Avatar
 
Join Date: May 2004
Location: houston
Posts: 2,262
Likes: 0
Received 0 Likes on 0 Posts
Car: 83 POS monte carlo 2015 chevy P/U
Engine: 92 5.7 tpi 5.3
Transmission: 700r4 6L60E
Axle/Gears: 2.42 too high
Re: Remember when I said my mileage was terrible?

A/C has little effect on my mileage.

Sonar, do you have a data log?
Old 01-27-2008, 07:03 AM
  #7  
esc
Moderator

iTrader: (6)
 
esc's Avatar
 
Join Date: Nov 2002
Location: North of Houston
Posts: 2,004
Likes: 0
Received 8 Likes on 6 Posts
Car: '82 Camaro 11.7@121
Engine: 377
Transmission: 400
Axle/Gears: Dana 44 / 3.31:1
Re: Remember when I said my mileage was terrible?

Originally Posted by Sonar_un
I don't have A/C.. and secondly it happens in the summer months as well as winter months. This has been going on and off now for a couple of years.

Maybe a weak O2 sensor? Working right sometimes...making it rich others?

A data log is probably your best bet for figuring it out. Especially if you can get one while you still have good mileage and compare it to when you don't.
Old 01-28-2008, 07:12 AM
  #8  
TGO Supporter

Thread Starter
 
Sonar_un's Avatar
 
Join Date: Nov 2000
Location: Houston, TX
Posts: 2,201
Likes: 0
Received 0 Likes on 0 Posts
Car: '86 T/A
Engine: 350/LT1 Intake
Transmission: 700R4 - Built
Axle/Gears: 4th gen 3.42
Re: Remember when I said my mileage was terrible?

I know i've logged it before and didn't see that much of a difference as far as the computer is concerned. I would have to take a look again, but unfortunately I have no idea when the car is getting good mileage vs when it isn't. The car drives exactly the same either way.

I think the only way to find out for sure would be to hook it up to a wideband and do it from there.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
InfernalVortex
Electronics
10
04-20-2021 11:31 AM
bjpotter
History / Originality
17
10-04-2015 07:48 PM
BrianI
Tech / General Engine
2
10-03-2015 12:57 PM
Eric-86sc
Interior Parts for Sale
1
09-28-2015 11:37 AM
mfp189
Transmissions and Drivetrain
1
09-27-2015 09:25 AM



Quick Reply: Remember when I said my mileage was terrible?



All times are GMT -5. The time now is 02:46 PM.