How Old Are Your Tires?
by Pat Goss
We get lots of inquiries from viewers about tires, and a big portion of those questions deal with street rods and collectibles. And the average question asks “I have a lot of time on the tires but not many miles. The tread looks good. Are the tires safe?”
Well, that depends on how the vehicle is used, and most street rods and collectibles aren’t used on the highway at high speed for long distances, so you’re probably okay. Speed and distance and heat; that’s the enemy.
Now, tires do go bad. They go bad naturally over time. If you look at this tire right here, it has great tread on it. But if we massage the sidewall a little bit, we see right in here that we have some serious cracks. This tire is dangerous. The bonding between the tread and the carcass of the tire, it’s starting to separate. And out on the highway this tire would probably fail.
Now, how long do tires last? Well, there’s a lot of debate, but mostly it’s accepted that six years or above you better think about replacing them.
How do you know how old your tires are? There’s a DOT stamp on the side of the tire, stamped right into the rubber. The last three digits of that DOT stamp tell you the year and the week within the year that the tire was manufactured. This one was manufactured in the 18th week of 1998. Now, from 2000 up it will be the last four digits. So when you’re buying new tires make sure they are new. Don’t buy old tires. Look at the date.
Now, pressure. Always a huge issue. You should have a tire pressure gauge in every car. Check the pressure regularly. Never exceed the pressure that’s stamped into the side of the tire, and rarely is that the pressure that belongs in the tire. To find the proper pressure you have to look at the decal inside the driver’s door on your vehicle.
Trailers are a huge issue. If you look at the comparison between this tire and the one on this trailer, you can see that the trailer tire is only about half the size of this one that would go on a tow vehicle. So half the size, it’s going to turn twice as fast. So when this tire is doing 60 miles an hour, that tire is doing 120. And the faster a tire turns, the more heat it generates and the more stress on the tire and the more chance for a blowout. So make sure that trailer tires are fresh, in good condition, and properly inflated.
* For more info on how to decipher the DOT code on your tire’s sidewall and determine the month and year it was manufactured, try these handy sites:
If you have a question or comment, write to me.
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