Hub Spacers?
 

Is there any concerns to performance / safety of vehicle when adding wheel spacers?

What are the recommended sizes for the front and rears when using the staggered 20" 214's?

Adding well designed spacers such as our ECS and H&R spacers with the proper lug bolts will have no safety effects on your E70. HERE is a pdf which shows you how to measure for spacers, I highly suggest using it as every ones idea of the ideal wheel location is slightly different. Once you make those measurements I have spacers from 2mm to 30mm HERE on the site, if you have any questions in regards to wheel bolt length or what size spacer you can use once you make your measurements I'd be happy to help you figure it all out.

James with ECS

^ note that the fenders won't actually rub with the wheel on the X5 because of the extra height... the pdf may be a bit misleading when it comes to that. I'd recommend either 10-15mm fronts and 15-25mm rears. Depends how bold you want to be. ;)

Standard response:

Some would say that you should never install spacers on any axle, for safety reasons. I'm in that club.

Spacers change the loading on wheel bearings by having the incorrect offset. Expect lower wheel bearing life.

Spacers change the loading on suspension components.

Spacers introduce an additional failure mode by having a second interface at the wheel attachment point. This is because there is now a bending moment applied to the wheel bolts. Safety margins can go down by a multiple of 2 or 3 very easily, even with narrow spacers. The affects of this one point can be partially mitigated by the use of proper hub centric spacers. Using quality spacers with correct hardware helps, but doesn't completely resolve this issue.

Spacers change handling by altering the steering geometry, particularly the scrub radius.

If you want wider looking wheels, the correct approach is to buy wider wheels with the correct offset. Using spacers is just a quick fix to the looks issue, specifically, the outer tire edge location relative to the fender.

That all said, many buy them just for the looks, don't care about the safety or handling issues, and haven't had problems. That's one approach.

Here is a link to a decent discussion on the impacts of using spacers, with further links to a good engineering discussion. Recommended reading.

http://www.xoutpost.com/bmw-sav-foru...l-spacers.html

Thanks JCL. I tend to agree with you... But since reading the BMW sites, I am seeing wide use of them. I've been "playing" with domestics primarily, I hadn't seen much use of spacers.

Thanks.