2005 BMW X5 4.8is tire & wheel upgrade
 

I'm thinking of running 21's with 285/35/21's and 325/30/21's. Has anyone done this ? Looking for some advise here?

Nope

This is going to get bumpy with such low profile tires.

Don't recall anyone going to 21s. If for looks most of us lower it about 2" to fill the wheel wells and many also add spacers of various widths based on what they like or their application. A side benefit is that lowering and widening the stance also improves handling.

For the Velocity 18 mm wheel spacers is that for the front and back or just the back wheels?

Chicago...with a La Nina winter approaching... and 21" tire/wheels... :yikes:

Hopefully you have a set of dedicated winter tire/wheels...and the 21 inchers will be for the spring/summer/fall. :)

Tires are like shoes...thus a tire designed for the environment it will be used in performs much better. For instance, would you wear flip flops when rock climbing, or wear hiking boots when doing water sport activities or going to the beach...or would you play football in ice skates, or go ice skating with golf cleats?

The AWD system is only as good as the tires mounted to the vehicle. Tires that can't handle the road conditions detract from an AWD system's ability to perform at its best.

Don't recall someone doing 21's on the e53. See them from time to time on the e70 as it was an available option on those.

I went wider tires on my aftermarket 20's... and wanted to keep more sidewall than 21's would allow. 285/40 up front and 325/35 out back. Also running 15mm spacer in the rear for an effective rear offset of +9. Semi custom wheels so lowest offset I could get was 24mm. Result.

https://s6.postimg.org/622fkvo1t/Brakes_18.jpg

Man all you need now is some X5M E70 Brembo upgrades behind those stellar wheels to bring that X5 to the next level!!!!

Crysatlworks by the way how did you incorporate the picture of your vehicle in the last post?

Oh I think I figured it out