Originally Posted by basora

19" or 20" OE BMW wheels will bolt on, but you have to look at:
- off set value of wheel
- center bore size (you X5 has 74.1mm CB)
- bolt pattern will be the same: 5 x 120mm

Your tires will be more expensive - $300 to $400/ea depending ...

If the wheels you are looking at came off a X6, they will have different size CB front and rear. You will need to modify the wheel (preferred method is boring out: from 72.56 to 74.1mm), or using "hub centric adapters" (less preferred method).

What style nr, brand and size wheels you are considering? Show pic or link if you have one.