Go Back   986 Forum - The Community for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Post Reply
 
LinkBack Thread Tools Display Modes
Old 04-07-2011, 07:18 AM   #1
Registered User
 
landrovered's Avatar
 
Join Date: Nov 2009
Location: Madison, Georgia
Posts: 1,012
Garage
Tire wear question

So the passenger side rear tire has worn in the middle 8" of the tread on two sets of tires. The fronts are fine and the drivers rear is fine but this is twice now that I am having to replace the rears because that tire wears out.

I could understand it if I was a drift person or a big burnout fan but I do not ever intentionally spin the tires. The diff is open, I wonder whether this is an alignment issue or if a LSD would solve the problem. It is a 3.6L and I do like to accelerate hard once I am out of first gear but I assumed that the PSM would minimize any wheel spin and I cannot hear it or feel it spinning. It feels completely hooked up.

Thoughts?

__________________
2001 Boxster S 3.6L, Zeintop
"Calling upon my years of experience, I froze at the controls." - Stirling Moss
landrovered is offline   Reply With Quote
Old 04-07-2011, 08:00 AM   #2
Track rat
 
Topless's Avatar
 
Join Date: Nov 2006
Location: Southern ID
Posts: 3,701
Garage
Air pressure, alignment or wheel spin. Over inflated tires tend to wear in the center. Under inflation tends to wear both outer edges evenly. Poor alignment tends to wear inner OR outer edge. What are your expectations? My car rarely sees straight line highways and spends a lot of time in the canyons. 5000 miles on a set of PS2 rears is typical for me.
__________________
2009 Cayman 2.9L PDK (with a few tweaks)
PCA-GPX Chief Driving Instructor-Ret.
Topless is offline   Reply With Quote
Old 04-07-2011, 08:11 AM   #3
Registered User
 
Join Date: May 2008
Location: Toronto
Posts: 2,656
Cheapest/easiest way is to check alignment and tire pressure.

PSM won't kick it until very late, it won't save you from tire wear.
ekam is offline   Reply With Quote
Old 04-07-2011, 09:32 AM   #4
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,709
Garage
Quote:
Originally Posted by landrovered
So the passenger side rear tire has worn in the middle 8" of the tread on two sets of tires. The fronts are fine and the drivers rear is fine but this is twice now that I am having to replace the rears because that tire wears out.

I could understand it if I was a drift person or a big burnout fan but I do not ever intentionally spin the tires. The diff is open, I wonder whether this is an alignment issue or if a LSD would solve the problem. It is a 3.6L and I do like to accelerate hard once I am out of first gear but I assumed that the PSM would minimize any wheel spin and I cannot hear it or feel it spinning. It feels completely hooked up.

Thoughts?
When I spin the tires the right rear center tread wears the most.

Minimize this by reducing to 33 psi. , rotate rear tires side to side, no need to replace tires in pairs.

PS: PSM first available in 2001
BYprodriver is offline   Reply With Quote
Old 04-07-2011, 10:42 AM   #5
Certified Boxster Addict
 
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,669
Alignment and/or air pressure.

Normally, the standard rear alignment will wear the inner 2/3's of the tire. The outer 1/3 barely sees any wear until you push the car hard in the corners and the camber changes to straighten up the tire so the outer 1/3 sees action.

If the alignment is off, then the car could be running mostly on the center 1/3 of the rear tire rather than on the inner 1/3 + center 1/3. This would tend to double the wear on the center 1/3.

If the air pressure is high, then the rears will wear more towards the middle as the air pressue will reduce pressure on the inner 1/3 of the tire and have the same effect as poor alignment.

Have a good alignment done and consider reducing the rear air pressure a few pounds.

Also, check the passenger rear for anything bent or worn like a wheel hub or suspension component.
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
thstone is offline   Reply With Quote
Old 04-07-2011, 11:00 AM   #6
Porscheectomy
 
Join Date: Mar 2006
Location: Seattle Area
Posts: 3,011
It may be the open diff instead of, or in addition to the alignment. If the transmission favors one side, you may be getting more wheelspin on one tire than the other. Could be due to some slight difference in suspension geometry or cv joint geometry on one side. In which case, LSD would help even tire wear. But I'd suspect the alignment of the rear suspension first.
blue2000s is offline   Reply With Quote
Old 04-07-2011, 11:32 AM   #7
Registered User
 
Join Date: Aug 2005
Location: Sanford NC
Posts: 2,533
And of course

the wheel itself could be bent.
mikefocke is offline   Reply With Quote
Old 04-07-2011, 11:35 AM   #8
Registered User
 
landrovered's Avatar
 
Join Date: Nov 2009
Location: Madison, Georgia
Posts: 1,012
Garage
Thanks for all the input...

We do have a good tire shop here with a four wheel alignment machine and I trust the guy because he lets me help. His staff puts up with all of my particular requests, hand torquing lugs with torque wrench and stuff like that.

I guess we can do the alignment when I get the new tires for the rear, I was looking today and the right is more worn than the left but the left aint looking too swift either.

The rears are Yokohama S Drives and they lasted me about one season (6k miles I would guess) the Michelins on the front look just like they did when the yokos went on the back. I think I may have to drop the extra coin and go with the Michelins on the rear as well.

Call it payback for all the excellent racing they sponsor around the world (and the stats for the pilots are superb).

If the alignment is spot on then an LSD might be in order.
__________________
2001 Boxster S 3.6L, Zeintop
"Calling upon my years of experience, I froze at the controls." - Stirling Moss
landrovered is offline   Reply With Quote
Old 04-07-2011, 11:44 AM   #9
Porscheectomy
 
Join Date: Mar 2006
Location: Seattle Area
Posts: 3,011
Quote:
Originally Posted by landrovered
Thanks for all the input...

We do have a good tire shop here with a four wheel alignment machine and I trust the guy because he lets me help. His staff puts up with all of my particular requests, hand torquing lugs with torque wrench and stuff like that.

I guess we can do the alignment when I get the new tires for the rear, I was looking today and the right is more worn than the left but the left aint looking too swift either.

The rears are Yokohama S Drives and they lasted me about one season (6k miles I would guess) the Michelins on the front look just like they did when the yokos went on the back. I think I may have to drop the extra coin and go with the Michelins on the rear as well.

Call it payback for all the excellent racing they sponsor around the world (and the stats for the pilots are superb).

If the alignment is spot on then an LSD might be in order.
6000 mile tire life would upset me and it sounds excessive, even for these cars.
blue2000s is offline   Reply With Quote
Old 04-07-2011, 12:47 PM   #10
Registered User
 
landrovered's Avatar
 
Join Date: Nov 2009
Location: Madison, Georgia
Posts: 1,012
Garage
Quote:
Originally Posted by blue2000s
6000 mile tire life would upset me and it sounds excessive, even for these cars.
Reminds me of the old Pirellis!
__________________
2001 Boxster S 3.6L, Zeintop
"Calling upon my years of experience, I froze at the controls." - Stirling Moss
landrovered is offline   Reply With Quote
Old 04-07-2011, 01:09 PM   #11
Registered User
 
Idaho Red Rocket 3's Avatar
 
Join Date: Oct 2010
Location: Nampa, ID.
Posts: 488
"Old Pirellis"! My Russos are wearing so fast you can use the rubber to repave the road. They are wearing about 1/10 per thousand miles on the front and 2/10 on the back.
Idaho Red Rocket 3 is offline   Reply With Quote
Old 04-07-2011, 02:29 PM   #12
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,709
Garage
Quote:
Originally Posted by mikefocke
the wheel itself could be bent.

and of course that would have zero affect on tire wear
BYprodriver is offline   Reply With Quote
Old 04-08-2011, 07:45 AM   #13
Registered User
 
Join Date: Oct 2008
Location: Waco, Texas
Posts: 388
I am having new rears put on today...

Quote:
Originally Posted by blue2000s
6000 mile tire life would upset me and it sounds excessive, even for these cars.
I got just over 27k miles out of the rears (falken azenis ST 115's) and they still have some tread left but the inner 1" edge of the tire is really worn. I am getting HTZR II's to replace them and get another alignment. I would be mad if I could only get 5-6k miles out of a pair of tires...maybe I am not driving it hard enough
papasmurf is offline   Reply With Quote
Old 04-08-2011, 08:03 AM   #14
Registered User
 
Join Date: Sep 2009
Location: Florida
Posts: 59
I bought directional tires,not to happy with the choice.
ocoeeboxster is offline   Reply With Quote
Old 04-09-2011, 11:03 AM   #15
Registered User
 
Join Date: Oct 2010
Location: Chadds Ford, PA
Posts: 177
Just looked at my tires. Fronts seem fine but the rears seem to be wearing on the outer portion of the tire. The inner part of the rear has a lot of meat left whereas the outer seems to have significantly less tread left.

Any thoughts on rear tires wearing like that?

Just checked the pressure after coming back from a ride so the tires/car is still warm.

fronts 235/40 18 reads 35.5 in both
rears 265/40 18 reads 36.5 in both
__________________
02 Boxster S (sold), 05 Boxster S (sold), 00 Ferrari 360 (sold), 05 Boxster S (sold), 01 Boxster S (sold), 99 Boxster (sold)

Last edited by SeaNile31; 04-09-2011 at 11:37 AM.
SeaNile31 is offline   Reply With Quote
Old 04-09-2011, 11:56 AM   #16
Registered User
 
tonycarreon's Avatar
 
Join Date: May 2009
Location: Frederick, MD
Posts: 1,396
Quote:
Originally Posted by papasmurf
I am getting HTZR II's to replace them...

HTZ R II or III ? i have the III and won't be buying them again.
__________________
"Speed has never killed anyone, suddenly becoming stationary... that's what gets you."
tonycarreon is offline   Reply With Quote
Old 04-09-2011, 12:22 PM   #17
Registered User
 
Join Date: May 2008
Location: Toronto
Posts: 2,656
Quote:
Originally Posted by SeaNile31
Just looked at my tires. Fronts seem fine but the rears seem to be wearing on the outer portion of the tire. The inner part of the rear has a lot of meat left whereas the outer seems to have significantly less tread left.

Any thoughts on rear tires wearing like that?

Just checked the pressure after coming back from a ride so the tires/car is still warm.

fronts 235/40 18 reads 35.5 in both
rears 265/40 18 reads 36.5 in both
You should have more wear on the inner part since it's negative camber all around.

You should also check tire pressure before you drive, not after.
ekam is offline   Reply With Quote
Old 04-09-2011, 12:40 PM   #18
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,709
Garage
Quote:
Originally Posted by ekam
You should have more wear on the inner part since it's negative camber all around.

You should also check tire pressure before you drive, not after.

You should have even wear on all tires unless you tell your alignment shop you would like to sacrifice treadwear for increased cornering capability.

Tire PSI increases 2lbs. during normal driving so keeping this in mind it is ok to check psi anytime just be sure before reducing psi on a hot tire.
BYprodriver is offline   Reply With Quote
Old 04-10-2011, 04:58 AM   #19
Registered User
 
Join Date: Oct 2008
Location: Waco, Texas
Posts: 388
They are the HTZ R II's...they have a higher treadwear rating...

Quote:
Originally Posted by tonycarreon
HTZ R II or III ? i have the III and won't be buying them again.
The car rides so much smoother now. You just don't realize how far gone the old tires are until you have new rubber.

papasmurf is offline   Reply With Quote
Post Reply


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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 01:27 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page