Problems replacing 20" and 21" tires

[ajob]

My X5 M was delivered with 20" Pzeros. Last winter I added a 20" winter set supplied by BMW.

Both sets were fine, never required balancing, the Pzeros felt increasingly better while wearing down.

At 32,000 km (20,000 mi) I had to replace the Pzeros. At higher speeds (above 85-90 mph) the car vibrated - and re-balancing the new tires did not help.

Switching back to the winter set the vibration disappeared. A complaint was lodged with the manufacturer who requested to send them back the tires for a check.

Then nothing happened for a while - until, with no prior communication, the tire dealer just got a reimbursement for the tires.

Next I looked for a new Pzero set, found one in England but delivery commitment was vague, 2-3 weeks, which made no sense.

So I talked to the BMW dealer who had sold me the car and they offered an "irresistible" deal for a 21" wheel set - I bought the rims only and then my tire shop sold me the Michelin PSS tires, paid with the Pzero reimbursement.

Big disappointment: the new Michelin PSS tires vibrated too, less than the Pzero but still very annoying.

While driving with them in Germany I explained the problem to the BMW online help and in five minutes they uploaded on my NAV the guidance to a top tire shop along my route.

There the technician found the wheels balancing to be OK, but noted "excessive wheel runout" in his report.

Meanwhile my home tire shop had notified Michelin and within a week they sent an Italian technician who very thoroughly inspected each wheel and its balance. He asked me to perform another check, to coast in neutral at high speed to see whether the vibration changed - I tried and told him that it made no difference.

Now the real surprise: three days later I get an e-mail from Michelin HQ in France stating that the inspection did not find any visible reason for the vibrations, but to ensure customer satisfaction, they would send me four new tires and have the old ones shipped to their central laboratory for additional checks.

Yesterday I mounted the new tires and now the car has no vibration at any speed - problem solved.

Michelin did this without any special "pull" from my side - I wouldn't know how to - but they certainly acquired a loyal customer, I will not forget how they treated me.

By the way: the switch from 20" to 21" is quite noticeable: directional stability and the ease of driving on high speed curves has improved a lot while the ride seems only marginally stiffer - and one really important good feature of the PSS tire is the thick rubber shoulder overhanging and protecting the aluminum rim - I twice grazed a kerb but it left no trace, while my 20" rims had lots of scratches due to similar "encounters".

[fatmatt0116]

this is good to know. I'm having a similar problem with the 21" Michelin PSS tires on my cayenne turbo s. I think I'll bring it to the dealership and see what they do for me.