BMW X3 Forum
BMW X3 Forum
Welcome to the ultimate BMW X3 community.
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
Post Reply
 
Thread Tools Search this Thread
      01-23-2013, 06:12 AM   #1
Gerber92
New Member
4
Rep
14
Posts

Drives: 2013 2.8 M Sport
Join Date: May 2012
Location: San Diego ca

iTrader: (0)

Anybody changed their tire size on 19' rim?

My X3 MSport rides a little bit stiff and bouncy. I'm planning to change the tires to non RFT and changing the tires size as well. Currently, i have the 245x45x19 an would like to put a 235x55x19. I appreciate if you could give me some insights.
Appreciate 0
      01-23-2013, 10:55 AM   #2
Amber
Private
8
Rep
77
Posts

Drives: 2012 X3 Sport 19" rims
Join Date: Oct 2012
Location: Ottawa, On.

iTrader: (0)

Tire change

I agree that a non run flat tire with a higher aspect ratio is really the way to go. The question is do you agree with BMW.CA who advise you not to change tire size.
Frankly, I do not believe that the small change in aspect ratio will have any significant impact on the X3, maybe a slight measure of change on the speedometer. But thats it.
Appreciate 0
      01-23-2013, 12:42 PM   #3
colson79
Second Lieutenant
7
Rep
221
Posts

Drives: 2012 X3 35i DSB
Join Date: Jul 2011
Location: Wisconsin

iTrader: (0)

You could change to non-run flats without any issues but I wouldn't change the aspect ratio on the tires. All of the electronics systems like stability control are calibrated to a specific tires size so you could run into problems. In fact I read a post on one of these forums where some changes the tires/rim with a different size than recommended and he was getting chassis stabilization errors. The problem went away when he put the original tires back on.
__________________
2012 X3 35i | Deep Sea Blue | Oyster |
Packages | Sports | Cold Weather | Cold Weather 2 | Premium | Technology | Premium Sound
Appreciate 0
      01-23-2013, 04:27 PM   #4
Amber
Private
8
Rep
77
Posts

Drives: 2012 X3 Sport 19" rims
Join Date: Oct 2012
Location: Ottawa, On.

iTrader: (0)

Quote:
Originally Posted by colson79 View Post
You could change to non-run flats without any issues but I wouldn't change the aspect ratio on the tires. All of the electronics systems like stability control are calibrated to a specific tires size so you could run into problems. In fact I read a post on one of these forums where some changes the tires/rim with a different size than recommended and he was getting chassis stabilization errors. The problem went away when he put the original tires back on.
Had a lengthy discussion with the folks at the Tire Rack they agree with BMW.CA you should not change the aspect ratio on 19" wheels. This would expose you to many potential problems. I take back what I said in my previous post.
Appreciate 0
      01-23-2013, 04:46 PM   #5
HighlandPete
Lieutenant General
6659
Rep
15,858
Posts

Drives: BMW F11 535i Touring
Join Date: Mar 2007
Location: Scotland, Highland Region

iTrader: (0)

If the F25 is as tire sensitive as the E83, I'd certainly be careful of changing tire profiles, particularly if you run a staggered setup.

There have been a lot of transfer box issues and drivetrain 'bunching' problems here in the UK in the E83, even changing from OEM 'star' approved tires. Usually gets back to wrong tire matching, even if using generic sizes.

HighlandPete
Appreciate 0
      01-23-2013, 04:51 PM   #6
brissim
Lieutenant
84
Rep
510
Posts

Drives: X3 30d (2011 F25) - now sold
Join Date: Jul 2011
Location: Brisbane, Australia

iTrader: (0)

Agree with comments here. Could have problems in going from 245/45/19 to 235/55/19. That is a 5.4% increase in tire diameter (38mm or 1.5") and besides the speedo error (speedo will read 5.4% low) may have problems with clearances and the cars electronics. In fact - don't know what your local laws are, but here in Australia the change would be illegal.

Tony
Appreciate 0
      01-23-2013, 04:59 PM   #7
brissim
Lieutenant
84
Rep
510
Posts

Drives: X3 30d (2011 F25) - now sold
Join Date: Jul 2011
Location: Brisbane, Australia

iTrader: (0)

Quote:
Originally Posted by HighlandPete View Post
If the F25 is as tire sensitive as the E83, I'd certainly be careful of changing tire profiles, particularly if you run a staggered setup.

There have been a lot of transfer box issues and drivetrain 'bunching' problems here in the UK in the E83, even changing from OEM 'star' approved tires. Usually gets back to wrong tire matching, even if using generic sizes.

HighlandPete
Had a long discussion with the service manager at my dealership about this. He confirmed that with the E83 yes there where major issues with the transfer case in changing tyre size from the OEM size and there was in fact a service advice never to do it. However (in theory) the improved X-drive system of the F25 is understood to have improved on this situation. From delivery (18months and 30,000 km ago) I've been running slighly oversized tyres (235/60-17 rather than the OEM 245/55-17) without issue. But this is only a 1.8% difference in tyre OD compared with the 5.4% of the OP and the nearly 10% difference one guy was running with and had problems with the electronics as colson79 had noted.

Tony
Appreciate 1
      01-23-2013, 08:10 PM   #8
Gerber92
New Member
4
Rep
14
Posts

Drives: 2013 2.8 M Sport
Join Date: May 2012
Location: San Diego ca

iTrader: (0)

Really appreciate the advice and insights on this tread. Now I'm stuck in my decision to either maintain the tire size and just go to a non RFT or change the tires size to a 235x50x19 which is about 3.5 ratio which is below the 5 (max ratio). Is there really a change in ride (not stiff and bumpy) when using a non RFT?
Appreciate 0
      01-24-2013, 09:43 AM   #9
Amber
Private
8
Rep
77
Posts

Drives: 2012 X3 Sport 19" rims
Join Date: Oct 2012
Location: Ottawa, On.

iTrader: (0)

Quote:
Originally Posted by Gerber92 View Post
Really appreciate the advice and insights on this tread. Now I'm stuck in my decision to either maintain the tire size and just go to a non RFT or change the tires size to a 235x50x19 which is about 3.5 ratio which is below the 5 (max ratio). Is there really a change in ride (not stiff and bumpy) when using a non RFT?
Let us know what you decide.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -5. The time now is 03:35 AM.




xbimmers
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST