I had major vibration issues on my '03 530i when I installed the 18" Style 37 M-Parallels. Turned out that the Pirelli P-Zero Nero M+S tires I installed were badly out of tolerence (3 of 4 were out of factory specs). It was pretty easy to find it on the Hunter machine. After faxing the results to the Tire Rack, they bought them back and replaced them with another brand at my request.

If your new 20's perform cleanly on the Hunter machine, the problem has to lie elsewhere (unless the person running the Hunter machine was not skilled or the machine was out of tolerence, either of which would negate my prior statement). However, in all honesty, I've never had a Hunter balance that was wrong (and I've had several). If the tires and wheels balance up on the Hunter machine and show no vertical or horizontal runout, then the problem has to be somewhere else other than the wheel or tire.

If your old wheels and tires run fine without any vibration and your new ones come up clean on the Hunter machine, then it would make me even more suspicious of the centering rings, especially knowing that the car was initially vibration-free for a time with the new setup. Remove the rings from the wheels and test fit them on the hubs to ensure they fit snugly and that they are not damaged in any way. Also ensure that the right ring is on the right wheel, if applicable.

Ultimately, as X5Andrew stated, they are warranted and you may need to exercise your rights in that regard, or at least get the company involved in problem resolution. Good luck!

Mike

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