poor gas mileage. Don't know why - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum
Go Back   Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum > Technical / Performance / Model > Mazda 6 1st Generation (2002-2008) > Engine / Drivetrain
New User? Register
Mazda6Club.com is the premier Mazda 6 Forum on the internet. Registered Users do not see the above ads.
User Tag List

Reply
 
LinkBack Thread Tools
Old 10-23-2009, 12:05 PM   #1 (permalink)
Registered User
 
Join Date: Jun 2008
Location: Vacouver, BC
Posts: 102
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Groans: 0
Groaned at 1 Time in 1 Post
iTrader: 0 reviews
Default

I have a 2004 mazda 6i with 110k. It normaly gets about 650 to 700kms per tank but lately it's been getting 550 to 575 kms per tank. I've cleaned the CAI filter, cleaned the MAF, and replace the spark plugs. I thought the low gas mileage might have been caused the advanced timing mod and the coolant bypass mod so I reverted the mods and the gas mileage is still horrible. I get not engine lights. I just replaced the passanger side wheel bearing and i think the passanger side CV might be going. Could a bad CV cause poor gas mileage? What else could cause the problem?

Cheers.
mahzda6 is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 10-23-2009, 12:11 PM   #2 (permalink)
Registered User
 
bmorrisj's Avatar
 
Join Date: Jun 2008
Location: OC, CA
Posts: 1,271
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 13
Thanked 195 Times in 137 Posts
Groans: 3
Groaned at 2 Times in 2 Posts
iTrader: 1 reviews
Default

tire wear/alignment?
seasonal change in fuel formulation at the pump?
__________________

2007 w/ Cheez

// COBB AP // SURE ID300 MAF // COBB TIP // CXRacing FMIC // PTP BSD // PTP Windage Tray // PTP TIG // KMD V2.1 CDFP Internals // HD Coil Packs //
Corksport DP // TurboXS RP // CP-e 3" Single Cat-back // Bilstein Shocks & H&R Springs // DSS Axle // TSW Interlagos 19x8 +35 // 235/35 Rubber
// Defi Red Racer // Block8head Defrost Pod // DDM 3k Fogs & 6k Lowbeams // Custom iPod Integration Hackjob //
bmorrisj is offline   Reply With Quote Quick reply to this message
Old 10-23-2009, 02:30 PM   #3 (permalink)
Registered User
 
Join Date: Jan 2008
Location: 95110
Posts: 248
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 2
Thanked 0 Times in 0 Posts
Groans: 0
Groaned at 0 Times in 0 Posts
iTrader: 0 reviews
Default

low tire pressure?
low compression on cylinders?
used different gas, higher octane rating?
bad wheel bearing?
brakes rubbing?
EGR stuck in closed position?
dirty TB?
lead foot?
what else?
__________________
2004 MAZDA 6S 5 DOOR HATCHBACK,STEEL GRAY, ATX
KNN CAI, MAGNAFLOW EXHAUST
TRUECOOL LPD TRANNY COOLER
EVOKE 17X7 GUN METAL RIMS, 225/45/17 ZR NEXEN N3000 TIRES
seigfredm is offline   Reply With Quote Quick reply to this message
Old 10-23-2009, 04:05 PM   #4 (permalink)
Registered User
 
Join Date: Jun 2008
Location: Vacouver, BC
Posts: 102
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Groans: 0
Groaned at 1 Time in 1 Post
iTrader: 0 reviews
Default

QUOTE (seigfredm @ Oct 23 2009, 11:30 AM)
Quote:
low tire pressure?
low compression on cylinders?
used different gas, higher octane rating?
bad wheel bearing?
brakes rubbing?
EGR stuck in closed position?
dirty TB?
lead foot?
what else?[/b]

tire pressure is fine, just replaced wheel bearing, brakes are fine, installed OTB two months ago, always use 87 octane gas, and I dont have a lead foot.

is it easy to clean the EGR? Where is it located?

mahzda6 is offline   Reply With Quote Quick reply to this message
Old 10-23-2009, 07:17 PM   #5 (permalink)
Registered User
 
Join Date: Jan 2008
Location: 95110
Posts: 248
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 2
Thanked 0 Times in 0 Posts
Groans: 0
Groaned at 0 Times in 0 Posts
iTrader: 0 reviews
Default

http://forum.mazda6club.com/index.php?show...p;#entry1237904

I'm not sure if it's the same set-up though
__________________
2004 MAZDA 6S 5 DOOR HATCHBACK,STEEL GRAY, ATX
KNN CAI, MAGNAFLOW EXHAUST
TRUECOOL LPD TRANNY COOLER
EVOKE 17X7 GUN METAL RIMS, 225/45/17 ZR NEXEN N3000 TIRES
seigfredm is offline   Reply With Quote Quick reply to this message
Old 10-25-2009, 04:33 PM   #6 (permalink)
Registered User
 
Join Date: Jun 2008
Location: Vacouver, BC
Posts: 102
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Groans: 0
Groaned at 1 Time in 1 Post
iTrader: 0 reviews
Default

QUOTE (seigfredm @ Oct 23 2009, 04:17 PM)
Quote:
http://forum.mazda6club.com/index.php?show...p;#entry1237904

I'm not sure if it's the same set-up though[/b]

is this correct picture of the EGR valve for the mazda 6i 2004?
Attached Thumbnails
poor gas mileage.  Don't know why-egr.jpg  
mahzda6 is offline   Reply With Quote Quick reply to this message
Old 01-07-2010, 05:08 PM   #7 (permalink)
Learners License
 
Join Date: Dec 2009
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Groans: 0
Groaned at 0 Times in 0 Posts
iTrader: 0 reviews
Default

QUOTE (dido123 @ Oct 23 2009, 08:05 AM)
Quote:
I have a 2004 mazda 6i with 110k. It normaly gets about 650 to 700kms per tank but lately it's been getting 550 to 575 kms per tank. I've cleaned the CAI filter, cleaned the MAF, and replace the spark plugs. I thought the low gas mileage might have been caused the advanced timing mod and the coolant bypass mod so I reverted the mods and the gas mileage is still horrible. I get not engine lights. I just replaced the passanger side wheel bearing and i think the passanger side CV might be going. Could a bad CV cause poor gas mileage? What else could cause the problem?

Cheers.[/b]
Have you had the car's ECU scanned for codes? I had mine scanned and found two O2 sensors stuck lean, which I believe would account for the poor mileage I've been having. Only thing is at over $120 each (and that's from Pepboys not the dealer) I don't drive enough to justify the cost versus money saved at the pump.
TDiddy is offline   Reply With Quote Quick reply to this message
Old 01-17-2010, 12:31 AM   #8 (permalink)
Registered User
 
Join Date: Jun 2008
Location: Vacouver, BC
Posts: 102
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Groans: 0
Groaned at 1 Time in 1 Post
iTrader: 0 reviews
Default

i had an oil change done a couple weeks ago and at the same time they updated the ecu. After the update the car was more responsive but still has poor gas mileage. The dealership said there were no codes. I was going to attemp to change the pvc valve today but its nearly impossible to remove the bolts. I will try it again another day. I am now getting around 530kms a tank. The car is feels sluggish and the other day the jerked a couple times during a hard acceration from start.
mahzda6 is offline   Reply With Quote Quick reply to this message
Old 01-17-2010, 01:43 PM   #9 (permalink)
Registered User
 
Join Date: Mar 2007
Location: KW Region, Ontario, Canada
Posts: 561
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Thanks: 4
Thanked 9 Times in 9 Posts
Groans: 0
Groaned at 1 Time in 1 Post
iTrader: 0 reviews
Default

QUOTE (dido123 @ Jan 17 2010, 12:31 AM)
Quote:
i had an oil change done a couple weeks ago and at the same time they updated the ecu. After the update the car was more responsive but still has poor gas mileage. The dealership said there were no codes. I was going to attemp to change the pvc valve today but its nearly impossible to remove the bolts. I will try it again another day. I am now getting around 530kms a tank. The car is feels sluggish and the other day the jerked a couple times during a hard acceration from start.[/b]
Cold weather would account for poor gas mileage. Also, the gas stations have winter additives to prevent freezing and w/e else and that too accounts for lowered mileage.
__________________

Mazda 6i Sport (Hatch, Onyx Black, 15% tint) 2007 - 5 Speed Manual Trans. MT-90 Oil
My Mods: Click Here For List of Mods - Turbo Charged.

Click Here for TSX Retrofit Instructions - Thanks Spidy
Polish_Eagle is offline   Reply With Quote Quick reply to this message
Old 01-17-2010, 03:49 PM   #10 (permalink)
Registered User
 
Join Date: Jun 2008
Location: Vacouver, BC
Posts: 102
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Groans: 0
Groaned at 1 Time in 1 Post
iTrader: 0 reviews
Default

it could be because of the winter gas, winter tires, colder weather but i have been experiencing poor mpg since september.
mahzda6 is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may 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



All times are GMT -4. The time now is 09:48 PM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.3.2