I've written before about the age of car tires and how it affects their performance. It seems old tires may have directly contributed to the death a few years ago of actor Paul Walker, well-known for his starring role in The Fast and the Furious movie franchise. Yahoo News reports:
A tire ... does two things: it sticks to the road by nature of its rubber chemical compound, and it disperses water using the tread pattern cut into the tire.
. . .
With collector cars, especially cars driven less than a few thousand miles a year, the problem is that while your tread may look good, the rubber is old and dry, and simply will not work properly. The chemical compounds in your tires will degrade over time, significantly reducing your available grip, or worse, blowing out a sidewall under load.
. . .
Roger [Rodas], an avid car collector with more than 50 cars to his name—including what I believe is the largest collection of Saleen cars in the world—had just bought himself a Porsche Carrera GT out of a long-term collection.
. . .
Once around the block was all it took to kill them both. The 3,500 mile Carrera GT was shod with its original tires. They, like the car attached to them, were 9 years old.
Roger lost control of the Carrera GT at an estimated 90 mph, and hit a tree.
The mainstream media, and indeed many automotive-focused web sites, simply couldn’t wait to report on the irony of the situation, that someone known for playing a character who drives crazy is killed in a supercar doing double the speed limit in an office park.
I was distraught the first couple of days, but honestly, all I could think about was how the crash happened, and I just kept going back to that day at Spring Mountain. This was a super low-mileage car. Roger was a really good driver. There were no other cars around or last-minute obstacles to avoid. It had to have been on original tires.
No one talked about the tires. Everyone wanted to hang Paul and Roger out to dry as their speeding scapegoats. The tires were a footnote to an exaggerated story, and it became a missed opportunity to teach a very real lesson. The LA Times reported one article on it nearly 5 months after the crash, and that was it. The cause of the crash was still ruled “unsafe speed for the conditions.” And not “tires, which may as well have been made of paper mache.”
There's more at the link. Recommended reading for automotive buffs.
It's not just collector's cars, of course - it's any vehicle with tires older than five or six years. I bought my pickup in 2005, fitted with Michelin tires that were already two years old at that point (according to their manufacturing date), although of course they hadn't been used at all except to get the vehicle to the dealer, and for test drives. I drove it on those tires until 2013. I now understand I'm fortunate not to have had one or more of them fail on me, particularly during occasional long-distance trips at steady, higher speeds. The rubber compound in the tires had aged to the point that it was no longer sufficiently flexible, and could no longer provide a good enough 'grip' on the road to be safe, particularly in wet, slippery conditions.
I recommend to all my readers that you check the date code on your tires right away. (If you don't know where to find it, see here.) If you live in a hotter, drier climate, and your tires are more than six years old, I strongly suggest that you consider replacing them at once, even if their tread is still within legal limits. Their rubber compound may have deteriorated to the point that they no longer provide as much grip on the road as you expect. If you live in a cooler, moister climate, they may be good for a little longer; but I'd check with an expert, just to be sure. As far as I'm concerned, living in Texas as I now do, where the summers (and the roads) get very hot, six years is going to be my guiding limit.
(Also, if you buy used tires, check the date code, and don't buy them if they're more than five or six years old. You'll be buying problems you can't see with the naked eye.)