Tires: tire replacement, defensive driving course, tire replacement

Question
Recently I attended a defensive driving course and was surprised to hear the
instructor state that tires should be replaced every seven years because of
deterioration of the rubber. Is there any truth to this statement?
Thanks for your help.

Answer
Bert,

Yes.

Rubber degrades over time, even if the tire is unused.  So time should be a consideration.

The recent advisories from the tire company say anywhere from 6 to 10 years.  My take on the difference is ambient temperature.

For example:  If you live in AZ, CA, NV, TX, or FL, 6 years would be the limit.  If you live in WI, MN, MI, MT. or ND, then it's 10 years.  And states in between are.......ah.......in between.