Wine and cheese can definitely improve with age. But those same passing years can have a detrimental affect on many other things, including your tires.
You’ve been told to replace them when they’re old enough that the tread is worn out. But you should also be checking your tires’ birthdays, and making sure they don’t go beyond their “best before” date.
There are no regulations on tire age, although Transport Canada recommends not using tires that have been stored for more than six years, and replacing all tires at ten years from the date of their manufacture.
Your tire carries its birthday on its sidewall, but right now, the code isn’t necessarily consumer-friendly.
It’s not always easy to figure it out, or even to find it, since it currently doesn’t have to be on both sides of the tire, and yours might be on the side you can’t easily see.
You’re looking for a three- or four-digit number at the end of the tire identification number, which is a series of letters and numbers that starts with “DOT.” If it’s a four-digit number, the first two are the week the tire was made, and the last two are the year: 4207, for example, means it was made in the 42nd week of 2007.
The number went to four digits in 2000, so if you’ve only got three, go back a decade: 218 means the 21st week of 1998. There’s also a possibility that it could be 1988, but in any case, a tire with only three digits is too old to be on a vehicle.
Tires wear as you drive on them, but as they age, they also dry out and become brittle, which can ultimately result in tread separation. Heat and oxygen are the main culprits, even in our cooler climate, since tires become very hot with friction when you’re driving.
They can also deteriorate just by sitting, no matter how well they’re stored. It’s especially important to check your spare tire, which typically remains in the trunk when you replace the other tires, especially if it’s a “doughnut” space-saver that doesn’t get switched around. It could let you down just when you need it the most.
While reputable tire shops and retailers rotate their stock regularly, it’s a good idea to check the manufacture date when you buy tires. It’s very rare, but possible that the “brand-new” tire you’ve purchased is actually very close to or even over its recommended shelf life.
There’s no regulation because the U.S. says it has to evaluate a reliable test method to determine a safe age, and evaluate the costs against potential safety benefits; Transport Canada says it’s because its investigations haven’t revealed a pattern of crashes caused by tire failure due to age at the time of sale. In other words, it’s up to you.
Check the pressure monthly, watch tread wear, rotate them regularly, and remember their birthdays.