At 07:17 PM 9/3/2008, Neil2 wrote...
>This is interesting.  How would the manufacturers tell (at the retail
>level)
>you've used a protectorant on the tire you're returning for warranty
>replacement?

They can't. The claim was that "All tire manufacturers advise not to
use any sealer or protectorants on the sidewalls...Most tire
manufacturers will also warranty ozone cracking for up to 4 years after
purchase or manufacture date (without receipt) unless tire
protectorants have been used."

That is simply not true.

For example, Michelin's warranty (
http://www.michelinman.com/media/en-US/pdf/tires/michelin-2007-limited-warranty.pdf
) says nothing about protectants (or "protectorants" [sic]). It does
say "Tires which become unserviceable due to alterations such as ...
use of tire dressing containing petroleum distillates are excluded from
warranty coverage." They're also covered for 6 years from date of
purchase.

The product I mentioned earlier, 303 Protectant, "does not contain
silicone oils or petroleum distillates, or other agents unsafe for
rubber, vinyl and other plastics," according to the manufacturer.