Hi Justin,
Not an expert but aware of the situation.
Tires begin to age harden from the day they are made. It is just an
extension of the original heat vulcanizing process, but at a lower rate.
A tire that was soft & flexible when it was made can become quite hard &
brittle as it ages. Heat, & UV from the sun can greatly increase the
aging/hardening rate. A tread compound with an original hardness of 60
on the "Shore A scale" can go to a hardness of 80 in a few years. A 33%
loss of traction maybe? For performance oriented drivers, the tires can
become harder & lose a noticeable amount of grip in a relatively short
time. Aside from traction loss, old, hard, rubber is more likely to
break. Many sports cars that travel limited distances can have 10 year
old tires with 95% tread, but the loss of original traction & more prone
to failure problems are there regardless.
As to whether six years is reasonable, who knows. It depends on how hot
the tires have been, how much UV light they have been exposed to,
original tread compound, etc. They definitely do age even if not used.
Slow selling types that are already three years old before sale, & have
been stored in the sun & in a hot location could certainly have much of
there original performance & safety margin used up before you ever buy
them. Apparently someone thinks they need to set a safe age for tires.
I personally won't drive on old tires, even if they have full tread. I'm
sure many others will disagree.
Dave Russell
BN2
Justin wrote:
> What do the tire experts think about the article below? Is this a real
> safety concern or are the OEM's trying to shield themselves from
> lawsuits? The tires on my Healey have to be nearly as old as I am (well
> maybe not that old...). What about my mom, she only drives ~ 3,000
> miles a year, her tire tread is going to last awhile.
>
> Justin
> Ypsilanti, MI
> 1961 BT7
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