An investigation into the accident that killed the actor Paul Walker revealed that the Porsche Carrera he was riding in had almost ten-year-old tires on it. The California Highway Patrol Investigative Group that researched the accident concluded that the tires’ age might have compromised Porsche’s handling characteristics and this may have played a factor in the accident.
Old Tires can deteriorate
For years, people have associated a tire’s roadworthiness with its tread depth. While this may be a factor in their condition but one must remember that the rubber compounds in a tire deteriorate with time. The result is that you may have a tire that is unsafe, despite the fact it has good tread on it and the tire looks good.
For many people, it’s not a factor
For many drivers, old tires are never an issue. If you drive a typical number of miles, somewhere around 12,000-15,000 miles annually, a tire’s tread will wear out in three to four years. This is long before the rubber compound in the rest of the tire does. The problem comes when one drives less. Say you drive only 6,000 miles a year or have a car that you only drive on weekends, aging tires could become an issue for you.
What happens to a tire as it ages?
Have you ever stretched an old rubber band and seen how it develops cracks? That’s essentially what happens to an old tire that’s put on a vehicle and driven. Cracks in the rubber begin to develop over time and this cracking can eventually cause the steel belts in the tread to separate from the rest of the tire. The result could be a complete failure of the tire under hard use.
How long does a tire last?
The National Highway Traffic Safety Administration (NHTSA) has no specific guidelines on tire aging and defers to the recommendations of the tire manufacturers. Most give a maximum life of approximately 6 years but Continental and Michelin say a tire can last up to 10 years, provided you get annual tire inspections after the fifth year.
How to determine the age of a tire
The sidewall of a tire is full of numbers and letters. Tires made after 2000 have a four-digit DOT code. The first two numbers represent the week in which the tire was made. The second two represent the year. A tire with a DOT code of 1109 was made in the 11th week of 2009.
Don’t Buy Used
We get it, tires are expensive, especially when you factor in the price of mounting and balancing. However, as the folks warn, the purchase of used tires is very much a buyer-beware situation. Even though a used tire may look great, it might be too old to use.
Of all your vehicle’s components, tires have the greatest effect on handling and braking. If you have an older car, check the build date on all your tires. If they are older than 6 years or so, consider buying a new set. Your life could depend on it.