Welcome to the North American Subaru Impreza Owners Club Sunday November 19, 2017
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...
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. 
Thread Tools Display Modes
Old 05-13-2006, 05:22 AM   #1
Scooby Newbie
Member#: 76127
Join Date: Nov 2004
Location: San Francisco, CA
2005 WRX wgn 5spd
Obsidian Black Pearl

Default Can I put different width of rims on front and rear?

I've got rota 17x8.

Can I put 225/40/17 for front and 235/40/17 for rear on my wagon?
* Registered users of the site do not see these ads.

Last edited by cinemaster; 05-13-2006 at 07:00 AM.
cinemaster is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 05-13-2006, 06:53 AM   #2
Scooby Specialist
Member#: 57307
Join Date: Mar 2004

The 40 isn't the height, but rather a ratio to the width.
I.e. the 225/40 has a 90mm tall sidewall or 3.54"
The 235/40 has a 94mm side wall or 3.7"

Good tool to help you see the difference in various tire sizes

As you can see the circumference has changed. Now the 225s are going 837revs/mile to the 235s 827revs/mile. This difference will have to be sorted out via the center diff and depending on the size/amount of the difference this would not be good for it, i.e. overheat and cook the diff. The difference in your case is very small, but you should check with manual IIRC it states no more than a 1 or 2mm difference in which case you would be over. Is this a case of Subaru being over cautious and just trying to CYA.......

Food for thought; some tuners suggest using the same size tire, but using a wider rim on the front. This is what your thread title says, but you ask about tire in your post. A 255/35 would be closer to the 225/40 than the 235/40.

I'm no expert so take what I say with a grain of salt.

Last edited by silentbob343; 05-13-2006 at 08:48 AM.
silentbob343 is offline   Reply With Quote
Old 05-13-2006, 07:06 AM   #3
Scooby Specialist
Member#: 73008
Join Date: Oct 2004
Chapter/Region: NESIC

well you shouldnt. with some quick math the 225 tire has a 24.08" height and the 235 tire has a 24.4" height. now i know somebody is going to say that within 3 or so % of each other is ok. you CAN put them on but it will cut the life of your center diff down an unknown amount. i would try to get tires that are the same height.

the math: section width = W, aspect ratio = A, rim size = R

((W*A)/25.4)*2+R = tire height

tire manufacturers will also have all their tires specs on their website so you can compare sizes.
seth_man is offline   Reply With Quote
Old 05-13-2006, 11:38 AM   #4
Scooby Guru
Member#: 86356
Join Date: May 2005
Chapter/Region: Tri-State
2016 Aprilia
Tuono v4 1100 Factory


The circumference has to be within 3%...not diameter.

His original question was about wheel widths, and there are people who have done that...but different tire sizes are baddd.
waktasz is offline   Reply With Quote
Old 05-13-2006, 12:26 PM   #5
Scooby Guru
Member#: 7958
Join Date: Jul 2001
Location: Plains of Eastern Montana
09 GH B+


You've also got the wrong relationship front and rear. With a AWD car you would generally want a wider combo up front, not rear (like a RWD)- ths will help dial out uneersteer.

The "easiest" way to accomplish this is to run the same tire front/rear- but run a wider rim up front say 8" front/7.5" rear- this gives you a little wider package up front (as a general rule section width increases ~ .2" per .5" of rim width increase).

You can run a different tire size combo, but you must be very cautious and get the heights very, very close (f/r)- proceed w/ caution w/ this endeavor.
BIGSKYWRX is offline   Reply With Quote

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
Question on Front and Rear Diff Service meridock Transmission (AT/MT) & Driveline 3 11-12-2004 03:58 PM
FS:Complete set of v7 STI Front and Rear seats redcoupe Mid West Subaru Owners Club Forum -- MWSOC 2 11-01-2003 03:34 AM
can I put tire load of 85v on my Legacy? etam Tire & Wheel 0 09-12-2003 07:46 PM
where can i find a pictures of rims on a black wrx uwilllose Member's Car Gallery 2 04-07-2002 05:22 PM
install on front and rear links, anyone do it? Keith Technical Forum Archive 5 05-18-2000 06:23 PM

All times are GMT -4. The time now is 01:58 AM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.