I agree with silver 5, although i opted for 20's and I too have an X5 3.0 and I was worried when I got the rims and tires. I didn't think it would fit but good thing it did.

I got the staggered size for the 4.6i which is 275/40 R20 in the front and 315/35 R20 for the rear. It looks way much better than the wimpy stock that it came with.

Still have to post some pics.

Good Luck Bimmer Boy! Post some pics when you've got them on so all can see.