Xdrive

[menelaos]

This may have been discussed before, but what's the maximum difference in height between front and rear tires that the XDrive can tolerate?
I know BMW does allow difference is tire diameter, but it's only a few millimeters.
Am thinking of buying staggered tires where the rear tire diameter is 0.6'' higher than the front.
Is this a problematic setup?

[DuSh]

If anything rear wheels should be smaller (by a tiny bit), not bigger (due to inherent xdrive design). Staying within 2% rolling circumference is max. Under 1% is recommended

So in your case 0.6'' difference in height yields 2.1% circumference difference (assuming you are using close to factory tire size) - it won't brake right away and you may even have no issues down the road, but you are pushing it (tire discount on particular set isn't worth potential expensive troubles with transfer case imho)

[menelaos]

No cheap, 22s Conti DWS06... Your advice is well taken.. Will not do it.