Q: We have a Corvette we use only for summer trips. It’s garaged the rest of the time. The tires have only about 22,000 miles on them. Treads look great, no sign of wear anywhere, and I think they’re about eight years old. I suppose tires, like all things, degrade some over time. How many more years can I get from them?
A: They’re already done in. Most manufacturers put the outside limit on tires at six or seven years, for exactly the reason you cite — they get brittle with age, more unpredictable, and the degradation is invisible to you. When tires are unused for long periods it speeds up the disintegration process because some protective chemicals are activated only when the tire is doing road travel.
Yes, I know — back to that six or seven years — that tire manufacturers have a strong interest in having you buy tires sooner rather than later, but understand this: the average number of miles a car owner drives annually is 13,476, according to the Federal Highway Administration. That means that in six years, most tires would have covered nearly 90,000 miles, a distance that would have prompted new-tire purchases. The low-mileage, longtimeframe drivers are such a small segment of the population it’s unlikely manufacturers would benefit much from stretching the facts for that group.
Not certain how old your tires are? There’s a series of numbers on the sidewall. The last four digits (provided the tire was manufactured after September 2000) will tell you the week and year it was produced. If the last four numbers are 0207, you know it was produced the second week of 2007.
© CTW Features
What’s your question? Sharon Peters would like to hear about what’s on your mind when it comes to caring for, driving and repairing your vehicle. Email [email protected].