[S58King]

Has anyone ran 20 inch all around on the xdrive and is there been any problems?

[Hawkdog]

Ran them all winter. No problems as long as fronts and rears are the same size (OD) tire.

[mydxb]

yes and problem

[S58King]

Originally Posted by Hawkdog

Ran them all winter. No problems as long as fronts and rears are the same size (OD) tire.

One more question i upped m rear is 295/30/20 is that bad?

[Hendo741]

Originally Posted by BrooklynG_M3

One more question i upped m rear is 295/30/20 is that bad?

If you have an xdrive and increased the rear diameter without upping the front, than yes it could potentially cause an issue with the trans and xdrive systems.

[fl1by]

This thread discusses this

https://g80.bimmerpost.com/forums/sh....php?t=1901031

[tooshay]

I don’t have any problems with 295x30x20. I’ve seen guys with 305x30x20 rears without problems.

[Limegrntaln]

Originally Posted by tooshay

I don’t have any problems with 295x30x20. I’ve seen guys with 305x30x20 rears without problems.

But are they 305s on an xDrive car. It's a totally different ball game. RWD doesn't care what size wheels you have, front to back. in AWD, all 4 wheels are connected to a certain point.

To the OP. It's not the overall size of the tires, front to rear, it's the variation in tire size, front to rear. The stock tire variance, front to rear, is .375% smaller, in the front, than the rear.

Simply going from say a 26.2" to a 26.8" overall size in the rear, while leaving the front size stock, could change the front to rear variance, by as much as 3% which would be waaaay out. To get the size closer, in the top of this post, you would need to change the rear tire to a 305/25/20 and then calculate that variance. but the 295 front from 305 rear, while keeping the overall 30 series, sidewall, won't cut it. 295/30 to 305/30, even though they are both 30 series, doesn't make the overall tire diameter the same, and just wider. The 30 is a "percentage" of the overall width, not an exact tire diameter. 295/30 means the sidewall is 30% as tall as the tire is wide.

[S58King]

Originally Posted by Hendo741

If you have an xdrive and increased the rear diameter without upping the front, than yes it could potentially cause an issue with the trans and xdrive systems.

So should I change my front 10 bigger also just checked the diameter difference is 1.47%

[S58King]

Originally Posted by Limegrntaln

But are they 305s on an xDrive car. It's a totally different ball game. RWD doesn't care what size wheels you have, front to back. in AWD, all 4 wheels are connected to a certain point.

To the OP. It's not the overall size of the tires, front to rear, it's the variation in tire size, front to rear. The stock tire variance, front to rear, is .375% smaller, in the front, than the rear.

Simply going from say a 26.2" to a 26.8" overall size in the rear, while leaving the front size stock, could change the front to rear variance, by as much as 3% which would be waaaay out. To get the size closer, in the top of this post, you would need to change the rear tire to a 305/25/20 and then calculate that variance. but the 295 front from 305 rear, while keeping the overall 30 series, sidewall, won't cut it. 295/30 to 305/30, even though they are both 30 series, doesn't make the overall tire diameter the same, and just wider. The 30 is a "percentage" of the overall width, not an exact tire diameter. 295/30 means the sidewall is 30% as tall as the tire is wide.

Should I go back to 285/30/20 in the rear?

[Limegrntaln]

Originally Posted by BrooklynG_M3

Should I go back to 285/30/20 in the rear?

1.47% I would venture to say, is too far out. You'd need to come under 1% comparatively, stock is .28% front to rear percentage

[Erebor]

Yep, you have to be within max. 1% of tire diameter difference for the xdrive to have a long and fullfilled life. There is also no need to give the rear more tire for traction purposes, because you have xdrive and therefore no issues with traction.

If you want to go 20" all around, do the same as I did and go for a 285/30 20" square setup. works and drives really well.

[exmowner]

Originally Posted by Erebor

Yep, you have to be within max. 1% of tire diameter difference for the xdrive to have a long and fullfilled life. There is also no need to give the rear more tire for traction purposes, because you have xdrive and therefore no issues with traction.

If you want to go 20" all around, do the same as I did and go for a 285/30 20" square setup. works and drives really well.

Would this be a proper way to calculate it?

The stock 275/35/19 front tires have a OD of 26.58in
The stock 285/30/20 rear tires are 26.73in
Dividing the two gets you a variance of 0.005

I was planning these sizes for my new wheels

285/30/20 front with an OD of 26.73in
295/30/20 rear with an OD of 26.97in
The variance being 0.008

Being under 1% should avoid any Xdrive issues?

[IAm3]

Thank you for this thread! I have 2 sets of OEM wheels and tires, and am debating if I can/should run 20's at all four corners without problems to the xDrive system. Along that same theme, if I run the stock 9.5-inch 19's at all four corners for a winter setup, can anyone foresee a problem using this 9.5-inch rim on 275/35/19 over BMW's recommended winter package which has 9.0-inch wide front rim?

[Team Tonka]

For my 2022 M3 Competition xDrive would I be able to use 275/30/20 winter tires/wheels without issue for the xDrive model?

From the factory I have 19” wheels up front and 20” in the rear.

Just wanted to make sure it doesn’t impact the xDrive technology due to swapping tire/wheel sizes.

[kiw1]

Originally Posted by IAm3

Thank you for this thread! I have 2 sets of OEM wheels and tires, and am debating if I can/should run 20's at all four corners without problems to the xDrive system. Along that same theme, if I run the stock 9.5-inch 19's at all four corners for a winter setup, can anyone foresee a problem using this 9.5-inch rim on 275/35/19 over BMW's recommended winter package which has 9.0-inch wide front rim?

This is what I'm planning to do as well, and from my research as long as you have the same rims and tires on both square setup's then it won't create an issue with x drive.

[jmg]

Originally Posted by exmowner

Would this be a proper way to calculate it?

The stock 275/35/19 front tires have a OD of 26.58in
The stock 285/30/20 rear tires are 26.73in
Dividing the two gets you a variance of 0.005

I was planning these sizes for my new wheels

285/30/20 front with an OD of 26.73in
295/30/20 rear with an OD of 26.97in
The variance being 0.008

Being under 1% should avoid any Xdrive issues?

You don't just divide the two, although you somehow kinda almost still got the right number.

To find the diameter difference, take the difference in diameters and divide it by the first diameter then multiply by 100 to find the difference between the first and second diameters.



26.73-26.97= -0.24

[-0.24/26.73]*100= -0.9%.

The front is 0.9% smaller than the rear.

Or just use this webtool:

https://www.omnicalculator.com/everyday-life/tire-size

[Erebor]

Yes, there are a lot of online tire calculators that do the job for you.
Just make sure you stay below 1% difference. You can go 275/285 or even 285/295, that is acceptable and is what bmw does on the M5 aswell.

[exmowner]

Originally Posted by jmg

You don't just divide the two, although you somehow kinda almost still got the right number.

To find the diameter difference, take the difference in diameters and divide it by the first diameter then multiply by 100 to find the difference between the first and second diameters.



26.73-26.97= -0.24

[-0.24/26.73]*100= -0.9%.

The front is 0.9% smaller than the rear.

Or just use this webtool:

https://www.omnicalculator.com/everyday-life/tire-size

Thanks for providing the formula, much appreciated.

At 0.9% I’m within spec.

[luckylingy]

+1 on advising to stay within 1% total circumference among all four tires, else your xDrive transfer case will expire prematurely. Not that anyone on this forum would do so, but don't run a new (replacement) tire without replacing the other three, if they're substantially worn. That will have the same adverse effect as running tires of different circumferences front/rear.

[kiw1]

Some good advice here, thanks fellas. I'm planning to run 19" 826Ms in the rear for winter with a new set of winter tires on my Xdrive. Glad folks are not having issues with similar setups

[IAm3]

Can anyone explain why BMW chose a 19 x 9.0-inch wide front rim for their winter package offering and not just stick with the standard 19 x 9.5-inch rim dimension?

I can’t believe 0.5-inch rim width difference would change the OD beyond the 1% tolerance???