Anybody changed their tire size on 19' rim? - XBimmers

Gerber92 · 01-23-2013, 07:12 AM

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.

Amber · 01-23-2013, 11:55 AM

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.

colson79 · 01-23-2013, 01:42 PM

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.

Amber · 01-23-2013, 05:27 PM

Quote:

Originally Posted by colson79

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.

HighlandPete · 01-23-2013, 05:46 PM

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

brissim · 01-23-2013, 05:51 PM

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

brissim · 01-23-2013, 05:59 PM

Quote:

Originally Posted by HighlandPete

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

Gerber92 · 01-23-2013, 09:10 PM

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?

Amber · 01-24-2013, 10:43 AM

Quote:

Originally Posted by Gerber92

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.

01-23-2013, 07:12 AM	#1
Gerber92 New Member Drives: 2013 2.8 M Sport Join Date: May 2012 Location: San Diego ca Posts: 13 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.
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01-23-2013, 11:55 AM	#2
Amber New Member Drives: 2012 X3 Sport 19" rims Join Date: Oct 2012 Location: Ottawa, On. Posts: 22 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.

01-23-2013, 01:42 PM	#3
colson79 Private First Class Drives: 2012 X3 35i DSB Join Date: Jul 2011 Location: Wisconsin Posts: 186 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

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01-23-2013, 05:46 PM	#5
HighlandPete Colonel Drives: BMW F11 535i Touring Join Date: Mar 2007 Location: Scotland, Highland Region Posts: 2,906 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

01-23-2013, 05:51 PM	#6
brissim Private First Class Drives: X3 30d (2011 F25) Join Date: Jul 2011 Location: Brisbane, Australia Posts: 175 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

01-23-2013, 09:10 PM	#8
Gerber92 New Member Drives: 2013 2.8 M Sport Join Date: May 2012 Location: San Diego ca Posts: 13 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?