Originally Posted By: MCompact
In my experience, if you don't have a staggered wheel tire set you should rotate them. The following article is courtesy of my friend Mike Miller, the Technical Editor for Bimmer and Roundel magazines:
Tire Rotation Examined
By Mike Miller
Initially, if your BMW has staggered tire and wheel sizing, meaning the rear tires are bigger than the front tires, click the little box in the upper right hand corner of your screen. You can't rotate your tires anyway.
BMW presently recommends against rotating tires. Here's why: In the US, it's normal to bend wheels occasionally, to one extent or another. And not all tires anywhere in the world are perfectly round. When a technician mounts and balances new tires, during the balancing process he will typically note which tire and wheel assembly is the "roundest", i.e., which has the least runout and requires the least weight to achieve 000 on the balancer. These two "roundest" assemblies he will mount at the front owing to BMW's incredible sensitivity to wheel balancing issues.
Then, down the road, the owner or another well-meaning tech rotates the tires front-to-rear. Next thing you know Old Jed's a millionaire -- you've got a vibration in the steering wheel. The reason is that one of the tire and wheel assemblies formerly at the rear and now at the front are not entirely round. If a technician rotated the tires, the customer then brings the car back to the shop complaining of a vibration, requiring a road test, dismounting, balancing, more road testing, etc. Often the customer will balk at paying for the additional work.
Moreover, at BMW dealerships, the customer satisfaction index (CSI) is hugely important in dealer relations with BMW of North America. When NA does a random CSI call on a service customer, scenarios like the foregoing result in comments like, "Well, I had my car at Big Mega Dealer and now I have a front-end vibration! So, I guess I can't give them a high score now can I?" The system is not set up for further explanation, and without that further explanation, the customer input impacts negatively on the dealer's CSI score. Eventually dealers complained to BMW of North America, and the end result is the no-rotation policy.
The thinking is, when you have a BMW that doesn't shake, leave it alone.
Now, armed with this knowledge, if you want to rotate your tires front-to-rear, there's no doubt that you'll get longer tire life. Just be aware of the possible balancing ramifications.
The presumption that the customer is incapable of understanding, or unwilling to understand, these issues is, unfortunately, often correct. However, Roundel Tech Talk takes the approach that it is better to at least attempt to educate people rather than throw out the baby with the bath water.
© 2002 Mike Miller
Is that fact or speculation?
