[Limegrntaln]

Originally Posted by 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???

Likely to adjust for a taller tire/ sidewall and still have the same turning clearance, inside the wheel well.

[Froz3n_M]

Ive used this calc in the past https://tire-calc.com, works well and easy to use. Stay within 1% as has been said for xDrive and you should be fine IMO.

You should also be weary of the tire brand, although a tire is 285 for example, it can vary by MM between brands, which can affect your numbers if youre running at the edge of tolerance youre looking at.

[mikewho_G82]

within 1% i think is a good rule of thumb. we need a real radial set up for the rear.

[pdjafari]

Doing the math the factory rear = 285/30/20 and I’m looking to run a 295/30/20 = +1.1%

Should I just keep the factory 285/30/20 as I’m now > 1%??

Looking to run 275/30/20 up front

[m4ml]

Originally Posted by pdjafari

Doing the math the factory rear = 285/30/20 and I’m looking to run a 295/30/20 = +1.1%

Should I just keep the factory 285/30/20 as I’m now > 1%??

Looking to run 275/30/20 up front

The size increase of the old rear to new rear is irrelevant. What matters is the size difference between the front and the rear.

In this case a 275/30/20 front and 295/30/20 rear would be a 1.9% difference and definitely out of range for xDrive.

A 275/30/20 front and 285/30/20 rear is a 0.8% difference, which should be fine for xDrive.

[markoz28]

There are literally dozens running 285/30/20 and 295/30/20 on Xdrive. I am one of them. Been running this set up for almost 7k miles on custom tune and and XHP. Zero (0) issues.

[BzsBimmer]

I’m running 285/30/20 and 305/25/21 on Xdrive with no issues