Results 1 to 20 of 61
Thread: WTF, on Gas Mileage
-
11-29-2008, 07:12 AM #1
- Join Date
- Aug 2006
- Location
- Michigan
- Age
- 54
- Posts
- 178
Black- 98 T/A
WTF, on Gas Mileage
Ok...
9,000 miles or so ago, I changed the plugs (irridium GM) plug wires, Seafomed the intake and a can in the tank cleaned the throttle body, Cleaned the MAF sensor correctly, cleaned the air filter, changed the diff lube, replaced the fuel filter. 7k ago, I replaced the O2 sensors.
I run a bottle of Seafoam through the tank every 6 weeks or so. Tire pressures checked every week.
I am getting 280-290 miles a tank on a 98 T/A. 80% of my driving is freeway, and I do not rag on her. T56
I did have a flange leak, drivers side, corrected 4 days ago. I have noticed the temp gauge barely creeps past 170-175, and it takes a long time to get there.
Is there anything else I should or could look at? Would taking it somewhere(first time in 10 years) and having a diagnostic be worthwhile?
I know she is tired with 139k, but she still idles well.
Am I being a bi-atch complaining about this, or is this mileage normal?Last edited by Banshee1967; 11-29-2008 at 07:17 AM.
-
11-29-2008, 09:26 AM #2
- Join Date
- Sep 2005
- Location
- Kentucky
- Posts
- 20
white- 2001 Trams Am
I have talked to 4 people here in KY in the last week that have all seen a drop of 3 MPG.
They are all over the state, so it isn't just a Louisville thing.
Motorcycles, cars, trucks. My car is off more like 3.5 MPG.
-
11-29-2008, 09:30 AM #3
- Join Date
- Oct 2007
- Location
- Beaver Dam KY
- Posts
- 7,745
79 T/A -91 Firebird- 1998 Trans Am -Oynx Black
WTF. Im having the same issue. Always get at least 280 miles a tank. Getting like 180 now. Im really confused
-
11-29-2008, 09:33 AM #4
- Join Date
- Aug 2006
- Location
- Michigan
- Age
- 54
- Posts
- 178
Black- 98 T/A
Replace your O2 sensors... That was exactly my problem 8 months ago..No SES light at all..replaced both sensors up front by the motor and my mileage went from 180-200 to 300. Not as good as 330-340 that I used to get.
I have a spare set of correct GM O2's if interested. They are the correct length and part #'s.
-
11-29-2008, 09:38 AM #5
- Join Date
- Oct 2007
- Location
- Beaver Dam KY
- Posts
- 7,745
79 T/A -91 Firebird- 1998 Trans Am -Oynx Black
Doubt its the 02s since i changed them recently.
Mileage drop basically happened overnight just as driven has explained. Changed out my IAT sensor and that helped a bit.
Where do you guys fill up?
-
11-29-2008, 09:42 AM #6
- Join Date
- Sep 2005
- Location
- Kentucky
- Posts
- 20
white- 2001 Trams Am
I use BP to get the 5% off.
People I talked to use everything from Kroger to Shell. I know my stepdad uses namebrand premium.
I wonder if they have slipped in some blended crap on us.
-
11-29-2008, 09:43 AM #7
- Join Date
- Aug 2006
- Location
- Michigan
- Age
- 54
- Posts
- 178
Black- 98 T/A
Which O2's? Are not there 4 of them? The two in the front are the ones I replaced.
Still 180 per tank was what I was getting..Replaced the fronts, and after a few days, went back to 300 per tank.
I had checked EVERYTHING else other than the o2's because there was no SES light. A few guys here said there were 4, but I replaced the front two in half an hour as Orion and SunsetOrangeSS suggested.
I have never filled up with anything other than BP 93.
-
11-29-2008, 09:44 AM #8
- Join Date
- Oct 2007
- Location
- Beaver Dam KY
- Posts
- 7,745
79 T/A -91 Firebird- 1998 Trans Am -Oynx Black
I only use bp premium. i have 1/16 tank of gas and i have to fill up in the next few minutes. Thinking of going to marathon.
The rear two do nothing.. I dont have them.. no cats
-
11-29-2008, 09:47 AM #9
-
11-29-2008, 09:49 AM #10
- Join Date
- Oct 2007
- Location
- Beaver Dam KY
- Posts
- 7,745
79 T/A -91 Firebird- 1998 Trans Am -Oynx Black
Winter blend?
Never had this issue since 05.
-
11-29-2008, 09:53 AM #11
-
11-29-2008, 09:56 AM #12
- Join Date
- Sep 2005
- Location
- Kentucky
- Posts
- 20
white- 2001 Trams Am
I've never seen this happen before and I'm 27.
Winter blend for diesel is the only chang eI know of. Gas would be a new thing.
-
11-29-2008, 10:03 AM #13
- Join Date
- Aug 2006
- Location
- Michigan
- Age
- 54
- Posts
- 178
Black- 98 T/A
I am on E now... Going to Shell and fill up. Will post results.
I wouldn't doubt that alot of the premium still in the tanks is from the $4.39 a gallon days a few months ago.
-
11-29-2008, 10:11 AM #14
-
11-29-2008, 10:13 AM #15
- Join Date
- Sep 2005
- Location
- Kentucky
- Posts
- 20
white- 2001 Trams Am
I know all about diesel fuel.
I've never heard of winter blend gas being used in KY.
-
11-29-2008, 10:25 AM #16
You gas just change to ethanol blended recently?
Our did this year (up to 10% Ethanol) and I noticed 30-40 miles less per tank. I now shop at NON ethanol blended gas stations if I can find them.
-
11-29-2008, 10:49 AM #17
-
11-29-2008, 11:43 AM #18
- Join Date
- Sep 2005
- Location
- Kentucky
- Posts
- 20
white- 2001 Trams Am
-
11-29-2008, 11:47 AM #19
I see you're in michigan. Do you let the car idle a while to warm up? Keep in mind that your gas mileage is always going to suffer a little during the winter. The car takes longer to heat up and stays open loop longer so it uses a little more gas.
-
11-29-2008, 12:23 PM #20
dude the most i ever got was 218 miles to the tank.....i wouldnt complain about 280.......i also never run the tank down past a quarter full
Thread Information
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
Similar Threads
-
Gas Mileage
By VOODOOII in forum External EngineReplies: 27Last Post: 08-24-2009, 08:10 AM -
Mileage
By JwMonE99 in forum LT1Replies: 32Last Post: 01-27-2008, 05:06 AM -
LS1 Gas Mileage
By LS1Powerhouse in forum Firebird / WS6Replies: 39Last Post: 06-29-2007, 06:14 PM -
bad gas mileage ls1
By waylonSS in forum General HelpReplies: 16Last Post: 09-23-2006, 04:10 PM -
3.73 gas mileage?
By jakef777 in forum DrivetrainReplies: 1Last Post: 09-11-2006, 01:07 PM
Bookmarks