Re: Is it ok to put passenger car tires on a boat trailer?
Rule of thumb is about 7 years. Funny thing is 10 years ago we didn't have any thumbs for that rule

. Or would it be , no rules for that thumb?
Regards,
With the economic turn down, some tire manufacturers aren't making or selling as many tires (others, like Cooper, have not lost much, if any, business)
So I suspect tires not shipped off to Africa or South America, will just set in a warehouse unsold.
I wouldn't buy a new tire that had been setting in a warehouse for more than two years. More boat trailer tires probably go bad from age than wear (not including misapplication).
I have an old Wagon I put new 80k tires on and then mothballed the car. In (7) years, the tires only got 3k miles on them. The Wagon was put back into service after (7) years. Within one week, all four of these expensive, premium tires had tread separation. (With about 90% of the tread left and the 80K warranty still in effect, the dealer put on a new set of 80k's for $50.00.)
From experience, age matters when it comes to tires.