Poor gas mileage - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


General GM Chat When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made. Chat about all things GM (and related cars). Off-topic stuff should be in the Lounge, and all Model specific mechanical problems should be posted in the proper forum.

Reply
 
 
 
Thread Tools Search this Thread
Old 02-08-2011, 06:48 PM   #1
Junior Member
Thread Starter
 
Join Date: Feb 2011
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
tootall67 is on a distinguished road
Default Poor gas mileage

Hello, just signed up to this forum. I went trough about 40 pages of threads, didn't see anything similar to my problem. The car is a 1996 Olds LSS, 3.8 non supercharged, which i purchased last October. The gas mileage is terrrible, about 16 mpg average. Did all the basic tune-up stuff, gained a 1 mpg. Also, no check engine light. Just wondering if anybody might have a rough idea, what the problem could be. Thanks.
tootall67 is offline   Reply With Quote
Old 02-08-2011, 07:04 PM   #2
Senior Member
Posts like a Northstar
 
bo58gardner's Avatar
 
Join Date: Apr 2010
Posts: 518
Thanks: 0
Thanked 0 Times in 0 Posts
bo58gardner is on a distinguished road
Default

Well for me that'* kinda average and brand new e.p.a. estimate was 17c/23h. I would like to say your at normal mpg but I am not a expert like Dan, Bill, Venom ect. But I'm pretty sure thats normal.
bo58gardner is offline   Reply With Quote
Old 02-08-2011, 07:04 PM   #3
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

Did you replace the O2 sensor? Also winter blend fuel kills mileage.
Danthurs is offline   Reply With Quote
Old 02-08-2011, 07:19 PM   #4
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

thats not normal, my wife gets 25 to 28 and she drives like john force. what exactly did you replace?
jwfirebird is offline   Reply With Quote
Old 02-08-2011, 07:48 PM   #5
Junior Member
Thread Starter
 
Join Date: Feb 2011
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
tootall67 is on a distinguished road
Default Poor gas mileage

Thanks for the responses so far, plugs, wires, air filter, is what i changed so far. The reason behind the question, was that i owned a 1995 Olds Regency Elite, before this car, I would average 25-30 mpg with that car, and straight highway, upper 30'*. So i am a little disapointed in the mileage i am getting. Thanks..
tootall67 is offline   Reply With Quote
Old 02-08-2011, 08:18 PM   #6
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

try fuel filter, then you might have to get into O2 like danthurs says
jwfirebird is offline   Reply With Quote
Old 02-08-2011, 08:29 PM   #7
Junior Member
Thread Starter
 
Join Date: Feb 2011
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
tootall67 is on a distinguished road
Default Poor gas mileage

Ok, thanks, I will try a fuel first. And, i thought a bad O2 sensor, would throw a check engine light on?
tootall67 is offline   Reply With Quote
Old 02-08-2011, 08:33 PM   #8
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

it may or may not, on the way to being bad could be less accurate.
jwfirebird is offline   Reply With Quote
Old 02-08-2011, 08:41 PM   #9
Senior Member
Posts like a Supercharger
 
flyballdog's Avatar
 
Join Date: Aug 2010
Location: Tweed Ontario Canada
Posts: 167
Thanks: 0
Thanked 0 Times in 0 Posts
flyballdog is on a distinguished road
Default

What 02 sensor would have an effect on fuel mileage?
The one in exhaust manifold or the one by the cat converter?
flyballdog is offline   Reply With Quote
Old 02-08-2011, 08:48 PM   #10
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

the downstream one just checks the converter

that reminds me, your cat could be starting to clog.
jwfirebird is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
poor gas mileage All Things GXP Your Other Rides: Pics & Videos 5 02-24-2008 10:52 PM
poor gas mileage LittleHoov General GM Chat 15 07-19-2005 01:36 PM
Tune-Up + O2 Sensor= Poor gas mileage? h1081dan General GM Chat 5 08-23-2004 10:56 PM
Poor gas mileage LSS Jim 1992-1999 7 03-22-2004 01:45 PM
Poor gas mileage SSEimatt93 1992-1999 14 08-04-2003 03:55 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 09:24 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.