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.)
Peter
10 comments:
911's can be squirrely cars on a good day and when you drive them like an idiot, they tend to swap ends.
Would new race rated radials help, sure but you still need to drive within your limits.
Gerry
I replaced the tires on my pickup at 10 years, even though: 1) the truck had been garage-kept (at both ends of the commute) and the tires were not subject to UV except while actually driving, and; 2) had fewer than 50K miles on them (FYI, they were premium Michelins).
I have a full second set (all 4 tires) matching the set on the truck, mounted on wheels and stored indoors in an airconditioned environment, on which the tires are 5 years younger than what's on the truck. The second set is mounted, balanced and stored at 3 PSI, and has snow chains mounted (I live someplace that experiences little snow but has the potential for ice storms) and I can change wheels in about 6 minutes per axle. When it comes time to mount them I'll inflate them to 30 PSI then.
When the road tires - which get balanced, inspected and rotated every 5K miles - become 10 years old the "second set" get moved to road duty and the road tires go inside and get the chains mounted.
FYI, if you're a prepper, get a second set of tires in the same size you regularly use. If you can find wheels that fit your vehicle to mount them, all the better (test them by driving on them for 100-200 miles, the deflate to 3-6 PSI and store them out of high temperatures - NOT in the garage or attic - and where UV won't reach them. They don't have to be the same brand, but they DO need to be the exact same circumference measurement. If SHTF tires, especially of the appropriate size, will be damn hard to come by.
Folks with full sized spares need to use that tire just to get to a tire shop. The spare on my truck is twenty years old.
How tires age varies greatly depending on use and storage conditions as mentioned above, but also depends on the manufacturer and the compound they use; the chemical formula can vary widely between and within brands in ways that affects the usable life.
You should look for signs of wear and damage beyond the treads - in particular, dry rotting or cracking of the side walls is something to keep an eye out for.
Age mileage and exposure to the elements, specifically smog and UV from the sun are the main factors. Low mileage tires on a vehicle that is garaged can get you ten years or more. A car parked outside in Phoenix can see the tire become brittle in five to six years. Your mileage (sic) may vary.
Ass-engined Nazi roller skates, as P. J. O'Rourke called the 911 (and he owns one) are tricky anyway.
As far as age vs. miles on tires, many bikers know this well, but more should. In colder climates, bikes are (by most) only ridden in good weather, & can accumulate more years than the miles would lead one to believe. I live in TN (surprise--wouldn't have guessed it from the name, wouldja?), but I still ride when it's cold. I've been known to have to stop & warm my (gloved) hands on the heads. Not everybody does that.
Tires are cheap, compared to the time you lose if you die, or the bad time you spend mangled & recovering, if you do (I'm crippled-up too, by the way, it just doesn't stop me from riding). You can't buy time.
--Tennessee Budd
I once put one of my motorcycles in a "time out" for several years because of a mechanical issue that I didn't have time to work on - I had another bike to ride, so fixing the broken one was a low priority. When I finally got around to fixing it, I didn't really think about the tires, which were hardly worn at all before it went into storage. I set out on a short 150 mile trip, and after arriving, noticed that large strips of tread had separated from the casing on the rear tire, and that I had been riding on bare casing. I thought the road felt unusually rough!
Yeah - tire inspection is more than just checking the tread wear.
I'm a bit of a tire junkie. I love tires. Living in the Midwest I keep a set of summer and a set of snow tires which in off seasons get stored in a climate controlled lower level of my house. A good scrubbing before storage keeps them fresh as does wrapping them with packing film. Keeping them out of the sunlight is critical. This is a huge deal for trailer tires. The sun kills tires fast. I cover tractor and equipment tires too if it doesn't get put in a shed. Don't buy the cheapest Chinese tires you can find at Wal-Mart either. The things are about as puncture resistant as wet toilet paper and have a habit of completely shredding the tread and disintegrating in the summer on the freeway. I've seen brand new chinese tires that were purchased for a summer trip shred at interstate speed. Not just one but 2 disintegrate and one suffer tread delamination during a cross country trip. That's not a fluke. Ever try to purchase tires in rural Alabama at 6pm on a Sunday? Good luck with that.
Back in '93 I bought an '84 Pontiac Sunbird from the original owner (whom I know quite well) that still had the original tires on it. The car itself only had 40K. Being a poor college student I couldn't afford to replace the tires right away. I took a trip out to Montana to see relatives and on the way back blew a front tire on the highway. Luckily I didn't roll the car. I got a bonus that fall and was able to replace the rest of the tires.
I just replaced all my tires - they were just under five years old, and my mechanic told me that they were unlikely to see me through the winter. I'll trust his judgement; it's more his area than mine. They still looked like they had a reasonable amount of tread to me, but apparently not enough to handle the winter snows safely.
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