offset
 

I was just wondering, will a set of 20" wheel off an e39 (offset+15, +13) will fit onto a '04 X3?

No. The offset of the X3 is 46mm, and 51mm for the rear if you have staggered wheels.

so what happens if i use a smaller offset, is it still ok?

It would probably hold the wheel in too far and contact the lower spring seat on the front struts. I've had a customer supply his own aftermarket crap custom wheels, wrong offset did just that. bolted them on, dropped it down, went to back out of the stall... wasn't gonna budge!

I got some good wheels with the correct styling, centering hub size, alignment pin holes, etc. In other words perfect fitting oem styling wheels in various styles from lakeshorewheelandtire.com. click the BMW specials link on the left of the page. I would check out the 19" 4.8 E70 style wheels for the X3... I think that would look sick!

Do you think those would fit OK?

They make them in that style for the X3, so they should fit perfect .

their x3 wheels page
http://i140.photobucket.com/albums/r...icture1-26.png

Thanks for the info. The E70 wheels which look like that are 20s.

Cheers
FB