PT Cruiser Forum  
Advertisements
       

Go Back   PT Cruiser Forum > General Forums > Tech & Performance Forum

PT Cruiser Forum

Advertisements
Sudden drop in gas mileage

 
Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 03 Nov 2009, 10:09 am
Fresh Cruiser
 
Join Date: Jul 2006
Location: .
Posts: 25
Default Sudden drop in gas mileage

Hi Guys.
My 02 Cruiser just turned 78,000 miles. Had plugs and wires changed at 74000 Car seems to running fine. Starts easy and runs smooth. Car has never burned a drop of oil.
So why is it I've had a significant drop in MPG over the past 2 or 3 months. Mileage has dropped from averaging 19-20 mpg to about 12-13 mpg, even less on some days..
Air filter is new. Tranny oil is clear and shifts great.
Is the old girl worn & tired or just sick???
I'm turning to the experts here on the forum for answers.
Any ideas would be appreaciated..
Thanks
PT Joe

Last edited by ptjoe; 03 Nov 2009 at 10:12 am.
Reply With Quote
  #2 (permalink)  
Old 03 Nov 2009, 10:38 am
Obsessed Cruiser
 
Join Date: Sep 2001
Posts: 27,744
Default Re: Sudden drop in gas mileage

The EGR and 02 sensors have a bit to do with the gas mileage but most of the time both things set off a fault code if they aren't working properly. You didn't mention the air filter, is it clean?
__________________
Rules of the forum have been updated as of *07/07/2019* Please read them over.

- All decisions by the Moderator are semi-permanent, can and may be changed at his discretion but definitely will be the final word. Any action performed by the Administrator or Moderators are not to be discussed on the forum.
Reply With Quote
  #3 (permalink)  
Old 03 Nov 2009, 11:06 am
Hooligan's Avatar
Obsessed Cruiser
 
Join Date: Aug 2003
Posts: 6,023
Default Re: Sudden drop in gas mileage

Quote:
Originally Posted by CREWZIN View Post
The EGR and 02 sensors have a bit to do with the gas mileage but most of the time both things set off a fault code if they aren't working properly. You didn't mention the air filter, is it clean?
He mentioned Air Filter is new!
__________________

2008 Silver Steel Metallic, Touring, NA, Sirius; Chromed door handles; lower grille; fog light surrounds; chrome front & rear bumpers strips; Airaid air filter; Bassani duals; Modesty Cover; Autolite AP5263 Platinum Plugs (.040); Crane Plug Wires; NAPA Ceramic pads; Blane hood struts; PTeazer Gas, Brake & Foot Rest Pedals, '05 Rear Step Pad, Stainless Door Sills, Llumar tint, "A" Piller chrome; APC Strut Bar
Reply With Quote
  #4 (permalink)  
Old 03 Nov 2009, 11:26 am
quicksilverdon's Avatar
Obsessed Cruiser
 
Join Date: Nov 2003
Location: Felton, Delaware
Posts: 20,501
Default Re: Sudden drop in gas mileage

I track all my mileage the old fashioned way - write down every fill-up.
You don't say where you are, but winter drops MPG by 1-2 for me, and that's not counting the drop in tire pressure.
What did you gap plugs at? Should be 0.040.
Have you changed gas stations/brands?
Keep those tires inflated!
Does your gas have a lot of ethanol in it that it didn't used to?
Throw some injector cleaner in - I hear Lucas is good.
__________________
"Anti-intellectualism has been a constant thread winding its way through our political and cultural life,
nurtured by the false notion that democracy means that 'my ignorance is just as good as your knowledge."
Isaac Asimov"

'05 Limited Turbo Lite, (Silver, of course)4-wheel ABS, Sunroof, Spoiler. Mods: E&G Classic grill, K&N FIPK, BTG duals, rear lowered 1.5", LED washer lights, $20 catch can, Aoogah horn, Weatherflectors, Sunroof Deflector, Fuzzy Dice, rear logo flames, rear pinstripe graphic, Gen3 Taillights, rear sway bar, hood struts, Strut bar.
Traded in '02 Silver Touring Edition w/87,000 miles
Reply With Quote
  #5 (permalink)  
Old 03 Nov 2009, 11:54 am
Fresh Cruiser
 
Join Date: Jul 2006
Location: .
Posts: 25
Default Re: Sudden drop in gas mileage

Quote:
Originally Posted by CREWZIN View Post
The EGR and 02 sensors have a bit to do with the gas mileage but most of the time both things set off a fault code if they aren't working properly. You didn't mention the air filter, is it clean?
Air filter is new, Less then 1500 miles.
I was thinking a possible emission problem but as you pointed out, I should have set off a code...Is there a gas filter on this buggy?
What type of MPG should one expect from a Michigan cold start to driving local roads on average less then 3 miles each day?
Thanks
PT Joe
Reply With Quote
  #6 (permalink)  
Old 03 Nov 2009, 02:22 pm
Obsessed Cruiser
 
Join Date: Sep 2001
Posts: 27,744
Default Re: Sudden drop in gas mileage

Quote:
Originally Posted by ptjoe View Post
What type of MPG should one expect from a Michigan cold start to driving local roads on average less then 3 miles each day?
Thanks
PT Joe
Less than 3 miles a day? It doesn't even get a chance to warm up. The 02 sensors don't come into play. The IAC/computer controls are dumping as much fuel into the throttle body as possible to keep the cold intake air and fuel in the proper mixture. Probably the worse scenario possible to try and get good fuel mileage.
__________________
Rules of the forum have been updated as of *07/07/2019* Please read them over.

- All decisions by the Moderator are semi-permanent, can and may be changed at his discretion but definitely will be the final word. Any action performed by the Administrator or Moderators are not to be discussed on the forum.
Reply With Quote
  #7 (permalink)  
Old 03 Nov 2009, 02:25 pm
quicksilverdon's Avatar
Obsessed Cruiser
 
Join Date: Nov 2003
Location: Felton, Delaware
Posts: 20,501
Default Re: Sudden drop in gas mileage

Gas filter is in the gas tank - I don't think that's it.

I'm in NW Joisey - coldest is zero, maybe 10 below - in Michigan in winter, I doubt you get warm in 3 miles.....
I drive 50 miles, takes about 2 miles beforer temp gauge moves in winter.
Reply With Quote
  #8 (permalink)  
Old 03 Nov 2009, 06:04 pm
Regular Cruiser
 
Join Date: Sep 2009
Location: Michigan
Posts: 135
Default Re: Sudden drop in gas mileage

Funny coincidence you mention Michigan. I noticed last winter in MI, my PT lost about 3 MPG with the cold weather. I only drove about 10 miles one way. Once it got warmer the numbers went back up.
Now I drive twice as far so I'm interested to see the difference.
But definately check your tire pressure.
Reply With Quote
  #9 (permalink)  
Old 08 Nov 2009, 12:36 pm
Fresh Cruiser
 
Join Date: Jul 2006
Location: .
Posts: 25
Default Re: Sudden drop in gas mileage

Quote:
Originally Posted by CREWZIN View Post
Less than 3 miles a day? It doesn't even get a chance to warm up. The 02 sensors don't come into play. The IAC/computer controls are dumping as much fuel into the throttle body as possible to keep the cold intake air and fuel in the proper mixture. Probably the worse scenario possible to try and get good fuel mileage.
Yea, you're probably right, although I've been driving this way for over two years now and only recently began to have this problem.
As someone here pointed out, I'm wondering if gas/ethenal may be to blame.
I've been getting most of the gas at Sam's Club.
I may try other brands to see the results.
Thanks for all the responses
Joe
Reply With Quote
  #10 (permalink)  
Old 08 Nov 2009, 12:54 pm
Young Cruiser
 
Join Date: Dec 2008
Posts: 50
Default Re: Sudden drop in gas mileage

my question, did the drop in fuel milage happen before or after you started to replace tune up parts?

Did you go from a better plug to a basic champion, wires oem quality or better or cheapo autolite ones?

How about the gas your using? same brand as before? Not going to go into the whole discussion about ethanol and all that but I get less MPG's with the 10% mix gas as I do with pure petro... Is it drastic? YES IMO, I usually get 3-5 mpg's better with pure gas then the 10% mix.

What changed?
__________________
2005, Cool Vanilla, Slate Grey interior, Turbo Vert'

Iridium plugs, K&N Typhoon intake..

Wrapped up in 16" Perelli rubber...

Viper remote start alarm system, JVC AVX-820 (7" LCD, AM/FM/CD/DVD/Bluetooth), 10" rockford fosgate with a 300w amp...

CLICKY, Jered's car domain page
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Why does my ac/heater all of a sudden feel like it's got something blocking the air? 85_305 Tech & Performance Forum 9 18 Aug 2009 05:20 pm
Mileage drop after replacing sensor........ Mohycle Tech & Performance Forum 2 10 Feb 2009 12:21 pm
Sudden whining out of my turbo pt artbumm General PT Cruiser Discussions 12 28 Apr 2007 04:03 am
Sudden drop in power justine311 Tech & Performance Forum 5 21 Feb 2006 11:24 pm
Sudden Engine Misfire VTX1800Dave General Turbo Discussions 22 07 Feb 2004 10:09 pm


All times are GMT -5. The time now is 10:07 am.




Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc.
vB.Sponsors