Welcome to the North American Subaru Impreza Owners Club Thursday December 18, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Click here to visit TireRack
Tire & Wheel Forum sponsored by The Tire Rack

Losing traction? Need new tires?
Click here to visit the NASIOC Upgrade Garage...
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Tire & Wheel

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 11-22-2004, 08:33 AM   #1
BoyRacer
Scooby Newbie
 
Member#: 31411
Join Date: Jan 2003
Chapter/Region: NESIC
Location: Upton Ma
Vehicle:
2001 RSTi, Cayman S
BRP Subaru, Black Cayman

Default How many new tires to buy?

Hi all,

I'm not 100% sure that I picked the right forum, but here it goes.

Last night I put two wheels off the road and bent my rims and wrecked the tires. They were my steel winter rims, so I'm not too crushed. I need an alignment now too, but hey, it could of been worse.

So now I need to buy at least 2 new rimes and tires, but should I get 4 new tires to keep the radius as close as possilble? The old tires on the car have LOTS of tred left, I only have about 7K-10K miles on them. Exactly how sensitive is the viscus limited slip diff on my 2001 RS?

Your advice is much appriciated.

Thanks,
MGB
* Registered users of the site do not see these ads.
BoyRacer is offline   Reply With Quote
Old 11-22-2004, 09:23 AM   #2
Boost-Free Subee
Scooby Specialist
 
Member#: 61052
Join Date: May 2004
Chapter/Region: NESIC
Location: Nashua, NH
Vehicle:
1999 2.5 RS
White

Default

it's not as critical as you might think. there are alot of more sensitive systems out there,(i.e. clutch pack; torsen, hildebrand) that are picky about very small differences in rolling diameter. the viscous diff is not nearly as picky. i wouldn't worry about it.
Boost-Free Subee is offline   Reply With Quote
Old 11-22-2004, 10:02 AM   #3
downeyer
Scooby Specialist
 
Member#: 10784
Join Date: Oct 2001
Location: Columbus, IN
Vehicle:
2002 WRX
Platinum Silver Metallic

Default

Statement straight from Subaru:

Quote:
On All-Wheel Drive (AWD) vehicles, it is extremely important that the rolling or outer circumferences of the tires be within 1/4 inch of each other. This means that you must physically measure the size of the tire. This is best done with the weight of the vehicle off the tire and at the tread centerline. Also be certain that the tires are properly inflated since this can affect your readings.

If you need to replace just one tire, the same holds true. The measured difference in circumference between the replacement tire and the other tires on the vehicle cannot exceed 1/4 inch.

Depending on the vehicle mileage, it might be better to replace all four tires.

If the vehicle mileage is low and the tires have been rotated and driven at the proper inflation pressures, then you may be within the allowable 1/4-inch difference in circumference.

If the difference between the new/replacement tire and the current tires is within this 1/4-inch maximum, then the tire should be compatible. If it is not, then other tires will need to be replaced to conform to the 1/4-inch rule.

Exceeding this 1/4-inch difference in tire circumference can place unnecessary wear on drivetrain components, possibly causing them to wear out prematurely.
So, I guess it depends. Are your tires within 1/4" circumference of a new set of tires? You could always have the new tires shaved or just bite the bullet and buy all new ones and sell your old tires to some FWD or RWD folks.

Even though many people try, it's difficult to argue with statements like this straight from Subaru.
downeyer is offline   Reply With Quote
Old 11-22-2004, 11:13 AM   #4
BoyRacer
Scooby Newbie
 
Member#: 31411
Join Date: Jan 2003
Chapter/Region: NESIC
Location: Upton Ma
Vehicle:
2001 RSTi, Cayman S
BRP Subaru, Black Cayman

Default

Thanks very much.... This is exactly the information I was looking for.

This sight is GREAT!

MGB
BoyRacer is offline   Reply With Quote
Old 11-22-2004, 11:17 AM   #5
Luke@tirerack
Tire Rack Moderator
 
Member#: 1215
Join Date: Apr 2000
Location: The Tire Rack
Vehicle:
800 -428-8355
ext. 4362

Default

7/32nds or more tread depth just get 2 new tires .... 6/32nds or less have the new ones shaved to match
Luke@tirerack is offline   Reply With Quote
Old 11-22-2004, 11:18 AM   #6
Boost-Free Subee
Scooby Specialist
 
Member#: 61052
Join Date: May 2004
Chapter/Region: NESIC
Location: Nashua, NH
Vehicle:
1999 2.5 RS
White

Default

a tire can exceed 1/4" difference in circumference by being over/under inflated. which has happened to me in the 5 years i've had the car. there is an importance, but 1/4"? sounds like a way for them to sell you alot of tires, or a loophole to void your warranty.
Boost-Free Subee is offline   Reply With Quote
Old 11-30-2004, 06:58 PM   #7
BigKuma
Scooby Newbie
 
Member#: 13060
Join Date: Dec 2001
Location: Longmont, CO, USA
Vehicle:
2000 Impreza 2.5 RSt
Silver

Default 1 New tire

I have the same problem. I ripped to pieces a 5 month old winter tire. The difference in tread between the brand new one I got and the 3 old ones is 3-4mm. I called about 20 shops in the area to find someone who "shaves tires". Nothing.

The machine is called "Trueing Machine", all the tire places know what I am talking about, but they either say :
"I have not heard about it in years" or "Call race shops".

Question:

Let's say I go with 1/4" rule and just install the tire. Where should I put it ?
My thoughts are:
1) Front would wear faster to make them even.
2) Rear would not affect the LSD (2000 RS) as much.

Mark
BigKuma is offline   Reply With Quote
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 Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
new springs, how many miles is to many on stock struts? pittsburghscoobie Brakes, Steering & Suspension 7 01-09-2010 12:25 AM
How many miles is to many miles to buy a Used Exhaust? OBPStiInMyEye Newbies & FAQs 17 06-14-2008 10:47 AM
How many are planning to buy a iphone SilverBoosted Off-Topic 540 09-18-2007 03:58 PM
So how many new WRX's are we going to have at the meet in march so far? BlueScooby New England Impreza Club Forum -- NESIC 7 02-23-2001 10:11 PM


All times are GMT -4. The time now is 05:28 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.