For retailers of new tires, the DOT preferrs that they be less than 4 years old to be sold as "new". 10 years is the max that they are allowed to kept in stock.
Having said that, as long as the tread and sidewall condition are ok, they should be fine. I have a set of Michelins on my Blazer that are 15 years old, they look just fine as far as wheather checking and trad condition.
