[Turbobusa]

If i purchase an X5M with the optional 21/22 inch 809M style wheels then change the wheels to the 21 inch style 741M wheels, does the car have to be reprogrammed for the new size in the rear?

[BiGFather]

Originally Posted by Turbobusa

If i purchase an X5M with the optional 21/22 inch 809M style wheels then change the wheels to the 21 inch style 741M wheels, does the car have to be reprogrammed for the new size in the rear?

I dont think so.

It would probably be only change in iDrive settings (where you have tires pressure etc).

When I change my wheels I just set in menu the winter tires + their size. Then measure the pressure and its done.

Mostly people have different sizes of their wheels for winter/summer and the settings "counts with that".

[Qsilver7]

Also, plus sizing & minus sizing isn't an issue when you retain the overall wheel circumference diameter.

This is part of the recommended & calculated tire sizes found either in the owners manual and door jamb. For example, if your vehicle came with 20" wheels/tires that are 245/35/20 (f) & 275/30/20 (r)...you can downsize to 245/40/19 (f) & 275/35/19 (r)...or if you want a square winter set-up you could go with 245/40/19 all around and the rolling circumference is the same or at least within 3% (+/-) which is allowable.

Look in your owners manual for the BMW recommendation for a 21" staggered tire set-up and use those numbers...or use the recommended 21" tire size for a square set up. If you run those numbers through a wheel/tire size calculator...you'll see that they are within spec of each other.