[GSH527]

Have you guys had alignments after changing tire sizes?

I'm going from a 19" winter set up to a 21" summer, wondering how it effects speed indication, lane departure, and wear on tires adversely.

[VTENGR]

Check and see if the outside diameter of the tire is the same. It seems that as the rim gets larger, the profile of the tire gets smaller, so the O.D. of the wheel stays approximately the same.

[Pro55]

Just select the new tyre size that is on the rear axle in the I drive and you are good to go. The system automatically updates the speedometer accordingly.
PS. As long as its the sizes approved by bmw. look in the I drive to confirm.

[eagle_bmw]

In addition to previous post, entering the correct tire size in iDrive enables the system to correctly flag loss of tire pressure, per manual (see TPM section).

[GSH527]

Originally Posted by eagle_bmw

In addition to previous post, entering the correct tire size in iDrive enables the system to correctly flag loss of tire pressure, per manual (see TPM section).

Thank you for these two posts.

Where in the I drive system can you find the tire size options?

[eagle_bmw]

Originally Posted by GSH527

Thank you for these two posts.

Where in the I drive system can you find the tire size options?

Here you go.

[GSH527]

Originally Posted by eagle_bmw

Here you go.

Awesome! Thanks again