"Bill Putney" > wrote in message
...
> Ray O wrote:
>
>> The UTQGS was developed to provide a uniform method of comparing tires,
>> and since mileage ratings are not part of the grading system, tire makers
>> have and use mileage ratings for "wiggle room" in their marketing.
>
> You're saying the mileage ratings (400, 620, or whatever) are not part of
> the UTQG? UTQG is only temperature and traction ratings?
>
> Bill Putney
> (To reply by e-mail, replace the last letter of the alphabet in my address
> with the letter 'x')

The uniform tire quality grading system has a treadewear rating with a
control tire assigned a rating of 100. A tire with a rating of 400 would
have a tread life that is 4 times the control tire; a rating of 620 would be
6.2 times, etc. Mileage is not necessarily the same as treadwear due to
differences in tread pattern and tire circumference, so rather than list
expected mileage, they compare tread wear.
--

Ray O
(correct punctuation to reply)