Old Tire Danger

Our Suburban had tires with 80% tread and less than 5 years old. On a trip to Arizona we had a tire sidewall blow out. The Suburban went out of control, hit and rolled over the divider and ended upside down in the fast lane of oncoming traffic. And that was only at 55 mph pulling an empty car tote. It was a serious accident but it could have been fatal. Fortunately none of us were seriously hirt.



I may be wrong but I believe most tire manufaturers recommend tires be replaced every four years. Regardless of how they look.



When I had my wheel alignment shop, I would often see tires that had lots of tread and the outer sidewalls looked ok, but the inner sidewalls would have serious major cracks. So don't forget to check the backside of the tires.



Also, the valve stems are often over looked. Bend them over, if there is any sign of a crack replace them. Sometimes they will break off when you do that. They are suppose to be flexable but over time they become hard and brittle. Better it happen in your driveway than out on the road.



Or a customer will only look at part of the tire with lots of tread and be blind to the part of the tire with little or no tread left, and think his tires are ok. However, tires will wear just as fast or faster on the thin tread as with lots of tread.



Then there is the inside of the tire that deteriorates which can not be seen as well as many other factors that affect tire life.



Keep tire pressure up. Low tire pressure and bad wheel alignment are the biggest killer of tires.



Have a good day. Lee

This is an intresting subject. I fear that it has a subject life much like talking about oil. There may be some merit it it but then again how much of it is hype and salesmanship. I do not fully understand how rubber wears; and have not made an indepth engineering evaluation of tires. I know that one of the major factors in rubber wear is the sun. The other is chemical exposure and wear and use.



For a point of discussion, I found a 1960 El Camino in a rock garage with hard packed dirt floor and no windows or light inside what so ever.. The tires were installed in 1966--High end SBR tires. I removed the car in 2006. Documented less than 2000 miles on the tires and forty years sitting above the ground with the car on blocks. I wanted the car judged so last year I bought a new set of bias ply tires. The tires that I took off were in perfect shape. Not a single crack or sign of wear anywhere. I gave the tires to a friend who now has them on his car.



Since we often drive our cars at 55 or below my advice on this subject is to inspect them often and keep them treated with products that protect them from the sun. Once I see a subjective report that is made by someone other than a news broadcaster I will reconsider my opinion.....

Thanks for the report. I found it good reading, however, I found any decision of the life of a tire to be inconclusive just as I expected. Below is a quote from section seven of the report that basically says they need more money to determine if they can figure out what their testing is telling them and if it has any thing to do with the failure of a tire under stress. I stand by my previous post.



"At this time, NHTSA’s research supports the conclusion that the age of a tire, along with factors such as average air temperature and inflation,

plays some role in the likelihood of its failure... However, the

agency must take additional steps before it can have a sufficient understanding of the aging phenomenon to support any possible safety

standard or consumer recommendations on the issue. Additionally, necessary cost and benefit analyses have to be performed before making any regulatory decisions."

This thread reminded me of my dad's 27 a few years back. He bought the car in 66 I think. It had the same tires on it until around 2000 or so, and there's no telling how old the tires actually were. The car spent most of the 80's in a garage with a bad flywheel so no miles were put on it for a good 15 years. In the mid 90's my brother got it going again, and my dad started driving it often. One summer, (2000 I think), the car had a blowout on the way to a cruise night. The tire literally disintegrated. The spare was installed and within a week did the same thing. At that point my dad bought a new set from Coker. Luckily, the car really is never driven over 45mph so there was no damage or injury, but it definately made us all think more about tire age.



I guess I'll have the same problem, my "New" tires are 5 years old and have 3K on them

Sunlight, heat, water and air, are the four factors in a tyre (our spelling!) deteroriating. Generally, if the tyre is kept on a wheel, inflated, and not exposed to sunlight or heat, it will last indefinitely. I'm talking here about the good old-fashioned cross-plies as fitted to our cars originally. Other factors leading to failure have been referred to - under or over inflationj, bumped sidewalls, etc. but if they are kept cool, in the shade, and not let go flat with weight on them, they will last indefinitely. I bought a 40-year-old 640.15 for my Jet at a swap meet 15 years ago. It had been bought for a trailer in 1955, by the vendors father, but never puton. it had been kept in a cupborad in his basement all those years, and never been exposed to sunlight. I did 30,000 miles on that one, and then took it off and had it recapped (yes we can still get that done here), and it is now awaiting it's turn to be put back on the car. Conversely, when I rebuilt my first '29 Hudson in '72, I bought a pair of 650.19's that had been stored for years in a loft in a local garage, right under the roofing iron. they looied fine, but after a thousand miles the treads had all split open exposing the canvas - a result of being exposed to high heat all those years. Water will rot the inside of a tyre, and they will blow out. But by and large, if you take sensible precauitons with cross-plies, they will last a very long time, but there is unfortunatelyno guarantee. My two-bob's worth!

Geoff.