[McLuVan]

Originally Posted by Malekreza11

What would you like to know exactly?

Most of what has been said is pretty accurate. Shank length is an important factor, along with the additional leverage produced by the increased track length per side from the OUTSIDE of the wheel hub. Running a wheel spacer is nearly the same as running a wider wheel, especially wheels with a deep dish. Deep dish wheels are substantially harder on wheel bearings than even a 20mm spacer would be.

If it makes anyone feel better, a mild spacer, such as 15mm, would not consitute enough leverage on the hub and bearing to cause premature failure. As it has been mentioned, the wheel bearing for high performance cars are designed to withstand a lot more than what a wheel spacer would do from a negative standpoint.