[Proper]

Originally Posted by Skyline2.0

I think Proper's comment takes into account the issues of a staggered setup (without smaller sidewall) resulting in one axle running with an overall larger circumference than the other axle. Without matching the overall tire and wheel circumference, one can run into driveline issues with mismatched circumference on front and rear tires. The X1's AWD Xdrive was not designed to run on two different types of wheel and tire set ups.