Steve wrote:
> Malt_Hound wrote:
>
>> Steve wrote:
>>
>>> Timothy J. Lee wrote:
>>>
>>>> In article >,
>>>> zerouali > wrote:
>>>>
>>>>> Tyre rotation seems to be a mainly American thing, no one else ever
>>>>> really mentions or uses it, as far as I've seen. Any particular
>>>>> reason for this?
>>>>
>>>>
>>>>
>>>>
>>>
>>> It all depends on what you're trying to maximize.
>>>
>>> If you're trying to extract the utomost performance from every tire,
>>> then don't rotate because once a wear pattern is established,
>>> switching it to a different corner of the car would result in a
>>> sub-optimal contact patch.
>>>
>>> On the other hand, if you don't expect to push your car to its
>>> absolute lateral G limit all the time (as in the case of 99.9% of
>>> daily driven cars!) then rotating the tires and tolerating a slightly
>>> sub-optimum contact patch right after rotation WILL get longer
>>> service life out of each tire.
>>
>>
>>
>> I don't uderstand the theory of this statement. If you are running a
>> tire which has worn a particular way, and now has a sub-optimal
>> contact, wouldn't you think that the "high spots" (the areas with
>> greater pressure in the new location) would wear faster and therfore
>> negate the total tire life assertion?
>>
>> -Fred W
>
>
> Yes, but the tire thus lasts longer than it would if you left it where
> it was so that it wore through to the cord in the first high-wear area.
>

I agree, rotation will lengthen the life of the individual tire, but the
tires will still wear at the same rate as a set.

Here's an example: Because of the large amount of rear camber, my Z3
wears the rear tires (on the inboard edges) twice as fast as the fronts
(which wear pretty evenly) . I can either replace the rears only at
~20k miles and get a total of 40k miles out of 6 tires, or I can rotate
the fronts to the back and thereby get a bit less than 30k miles out of
the original set of 4, and then have to buy 4 new tires.

Plus you either have to swap the wheels yourself or pay someone to do it.

-Fred W