Skip to main content
ask joanne

I just had my vehicle serviced, and the dealership tells me I need new tires. I think they're just trying to make money. My tires look fine, they've got plenty of tread and I've only driven 24,000 kilometres since I bought them eight years ago. When I called them on it they said my tires are old and that tires are only good for a limited time period before they become too hard. Are they trying to rip me off? – Don in Dartmouth, N.S.

Unlike port or a fine single malt whisky, tires don't improve with age. Whether they're attached to a vehicle or stored in the cellar, tires do degrade over time.

But how long do tires usually last? This, of course, depends on the type of driving you're doing, the conditions and how much you drive. Are you a constant highway cruiser, an off-road explorer, a Sunday stroller or still racing around with a bout of Saturday night fever? If you're burning a strip each time you leave the lights, then you're going to be more of a regular down at the service centre.

Besides the more obvious degradation through use, under- or over-inflation, overloading your vehicle, climate, road hazards, improper maintenance, structural defects and improper installation, tire aging is something to be aware of. Even if your tires are only used occasionally, or they're just sitting in the garage under cover, the structural integrity may be weakened over time even though plenty of tread remains. They may look completely fine on first inspection, but may need to be checked and possibly replaced.

So is anyone regulating this? Well, the U.S. National Highway Traffic Safety Administration, which writes and enforce safety standards for motor vehicles and regularly studies the effects of aging on tires, says: "While tire life will ultimately depend on the tires' service conditions and the environment in which they operate, there are some general guidelines. Some vehicle manufacturers recommend that tires be replaced every six years regardless of use. In addition, a number of tire manufacturers cite 10 years as the maximum service life for tires. Check the owner's manual for specific recommendations for your vehicle. Remember, it is always wise to err on the side of caution if you suspect your vehicle has tires that are over six years of age."

Transport Canada does not regulate the age, shelf life or useful life of tires. They do, however, require the date of manufacture to be moulded on the sidewall of every tire. Under the Motor Vehicle Safety Act, Transport Canada develops, maintains and enforces the Canada Motor Vehicle Tire Safety Regulations. These require that all tires have a Tire Identification Number (TIN). This is a string of letters and numbers that are moulded on the sidewall of each tire, and includes the tire date of manufacture.

The last four digits of the TIN correspond to this date. The first two digits represent the week of manufacture, and the last two represent the year. Note, however, that while the TIN appears on both sides of the tire, the manufacture date code appears on only one side.

I also talked with the owner of a tire shop. I know what you're thinking, and of course his business is selling tires, but he gives some fair advice. "The rule of thumb for the lifespan of tires is five years," says Al Premji, owner of Vancouver's ABC Tire.

"After about five years, the rubber becomes hard and, even if the tires are looking good, the traction reduces and weakens quite dramatically, actually. Some people don't realize that, they think their tires are fine just by looking at them, but they're not."

Perhaps the most interesting thing he mentioned is that, if new tires remain unsold on his shelves after two years, they're sent back to the manufacturer. "Manufacturers are really careful these days with what they carry, and how long they're left on the shelf." These profit-thirsty manufacturers wouldn't be replacing new stock if they didn't have a shelf life.

When it comes to wheel safety issues, I wouldn't take any chances. Replacing your tires may be pricey, but not as much as replacing your vehicle, or worse.

More generally, I would apply common sense for the first five years, watching the tread and overall state as you normally would, and replace if they are approaching the recommended limit of wear and tear, or have any major issues. After five years, and this obviously applies in your case, I would have them checked, and if necessary play safe and replace them. Don't forget to have the service centre check your spare while they're at it.

E-Mail your car questions to Ask Joanne at