Tires are some of the most important components on your vehicle, as they're the only contact the vehicle has with the road. So, when buying new tires, it's essential you understand the ins and out of tire shopping in Canada. 

This includes understanding the various measurements and ratings, tire design and intent, and the range of tire warranties available.

With all this information at hand, you'll be in perfect shape to head out and buy replacement tires confidently, so let's dive right in. 

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Tire Measurements

When buying tires in Canada, you’ll focus on four key measurements: size, load rating, speed rating, and treadwear. 

Tire Size

When shopping for new tires, the first number you must know is the tire size. In almost every case, all their measurements, other than the rim size, will be in millimetres (mm). You'll find the recommended tire size for your vehicle on the tire placard on the driver's or passenger's side door frame. The size will be formatted in this way: 225/60R16. 

On the tire, you'll find this number stamped on the sidewall. 

The first three numbers are the tire's width in millimetres. The second two numbers are its sidewall height as a percentage of the width -- in the example size, it's 60% of 225 mm. This "R" simply means it is a radial tire -- in some cases, there may be a "Z" before the "R," indicating this is a high-performance Z-rated tire. The final two numbers are the rim size in inches -- Our example tires fit a 16-inch rim.

In rare cases -- typically only in pickup truck and SUV tires -- tires will come in inch measurements, such as 33x12.5R18. These tires are 33 inches tall by 12.5 inches wide and fit 18-inch rims. 

When engineers design a vehicle, they do so to specific weights and sizes for everything, including tires. This means the factory tire size for your vehicle is what the engineers say is best for your vehicle's performance, fuel efficiency, and safety. You can stray from these size recommendations slightly, such as moving from a 225/60R16 to a 235/55R16, but this could negatively impact the vehicle's performance or fuel efficiency. 

Tire Load Rating

The tire load rating is the weight capacity of each tire. You can find the recommended minimum load rating on the tire placard. You’ll find this two- to three-digit number stamped immediately after the tire size on the sidewall. 

Unlike the size, the number doesn't directly translate to a measurement. Instead, you must refer to the load rating scale to decipher what the number means. For example, a tire with a 99 load rating can hold up to 775 kg, so a set of four of these tires can support up to 3,100 kg. 

You can always get a tire with a higher load rating and not impact the vehicle's performance. However, you never want to get a tire with a load rating lower than the manufacturer's recommendations, as this reduces the recommended weight capacity for the vehicle. This is particularly important in trucks and SUVs that do a lot of hauling.

Tire Speed Rating

The tire speed rating is the single letter directly following the tire load rating. It indicates the highest speed a tire can handle without losing its ability to function as designed. 

Speed ratings range from A1 (5 km/h) to Y (300 km/h), but most tires will fall between S (180 km/h) and Y (300 km/h).

Like the load rating, you need a tire speed rating scale to translate the letter's meaning. For example, a tire with an H speed rating -- traditionally the beginning of the "performance tire" segment -- can handle speeds up to 210 km/h and still function as designed.  

There is also the ultra-high-performance range of tires known as Z rated. These are any tires that can handle 240 km/h or higher. These will generally have a "Z" before the "R." In some cases, they may also have a "W" or "Y" following the load rating. W- and Y-rated tires still fall under the "Z" category, but they can handle speeds up to 270 km/h and 300 km/h, respectively.  

Treadwear Rating

All tires wear differently depending on their rubber compound and the type of driving they're intended for. The treadwear rating gives you an idea of how one tire will wear relative to another. 

The treadwear rating is almost always a three-digit number and is based on the tire's longevity throughout an 11,587 km drive on a test course in Texas. The wear rating is given relative to a course monitoring tire. The course monitoring tire is always a 100 rating, so if a tire displays double the tread life after the 11,587 km drive, it will receive a 200 score. 

Because manufacturers can choose their own course monitoring tire, this rating is truly only effective when comparing tires within a specific brand. 

Tire Design and Intention

With the right tire measurements hand, you must also look into the tire's design and intentions. 

Tread Pattern

The tread pattern is particularly important, as this shows you what the tire is designed for and how it will perform in varying conditions. 

A standard all-season tire will feature medium-sized tread blocks -- uninterrupted blocks of rubber -- with small slices known as sipes in them to help with grip in ice and snow. They will also feature deep channels between the tread for water and snow to go into, allowing the tread blocks to have maximum traction in bad weather. All-season tires are generally designated by an "M+S" marking, meaning mud and snow, somewhere on the sidewall. 

A high-performance or summer tire will have large, nearly flat tread blocks for maximum dry grip. They will have channels between the tread blocks for wet weather, but generally lack the sipes of an all-season tire, making them unsuitable for snow and ice. These tires also generally have a softer rubber compound than an all-season tire. These tires are not suitable for cold-weather driving, as the rubber compound becomes brittle and can break apart when the temperature nears freezing. 

Winter tires are special tires designed for use in cold Canadian winters. They have a unique rubber compound designed to remain soft in freezing conditions and generally have more aggressive siping for extra grip. In some cases, winter tires also have pre-installed metal studs, or you can have them installed, for extra grip on ice. Winter tires are easy to identify by the stamping of a snowflake inside a three-peaked mountain on the sidewall. Winter tires are not suitable for summer driving, as the rubber becomes too soft and wears quickly. 

All-terrain tires are designed specifically for light trucks and SUVs. They put together the open tread design of a true off-road tire with an on-road tire’s large flat tread blocks. This allows you to do light off-roading without worrying about mud clogging up the channels and causing you to lose traction while also allowing you to drive at highway speeds without the mind-numbing drone of off-road tires. 

Sidewall Strength

There are three sidewall variations on passenger car tires, each with its own intent. 

The standard tire sidewall is about 3.2 mm thick, which is more than enough to support most vehicles. However, when they lose pressure, this thin sidewall cannot support the vehicle's weight. You must either inflate the tire or install the spare tire and drive to a shop for a repair. 

A run-flat tire has a roughly 19 mm sidewall that allows you to drive a short period at lower speeds with little to no air in the tire. Generally, you can drive up to 80 km at up to 80 km/h on a depressurized run-flat tire. 

The third sidewall variant is an XL, which stands for "Extra Load." These tires have thicker, reinforced sidewalls to support a larger vehicle's weight. Generally, you'll see these on large vans and SUVs. If the vehicle came with XL tires, you must replace them with XL tires or risk severe safety issues. 

Tire Warranties

Tire warranties are very often misunderstood and for good reason. They can be downright confusing. Most tires have three warranty types: workmanship, tread life, and road hazard. 

Workmanship Warranty

Most passenger car tires sold in Canada will have at least a workmanship warranty. This covers the tire against structural defects for a specific number of miles or years. These warranties usually don't cover the tread life or punctures. Instead, they cover against things like cracking, splitting, belt separation, bubbled sidewalls, and more. 

Tread-Life Warranty

Many general-use tires come with at least a short tread-life warranty, such as a 65,000 km. This means the tire is guaranteed to last at least 65,000 km before needing to be replaced, so long as you follow the tire rotation schedule and keep the vehicle's alignment within specification. 

These warranties are usually prorated, meaning if you got 32,500 km out of a 65,000 km warranted tire, you'd get a 50% credit toward a replacement.

Tread-life warranties do not cover punctures or other damage. 

Road Hazard Warranty

A road hazard warranty is an extra warranty on top of the manufacturer's warranty and typically costs extra. Road hazard warranties cover punctures, including nails, sidewall damage, and blowouts due to potholes.

Most road hazard warranties cover puncture repairs 100%, but unrepairable tires usually are replaced at a prorated amount, depending on the amount of tread left on the tire. So, if the tire originally had 8 mm of tread and now had 4 mm left and it is unrepairable, the road hazard warranty would give you a 50% credit toward a new tire.

All Clutch Pre-Owned Cars Come With Plenty of Tread Life Remaining

When shopping for a pre-owned vehicle, you should always inspect the tires. Check their tread depth and see how much life they have before they need replacing. If you fail to check this, you could end up with a vehicle that needs new tires just months after buying it, setting you back hundreds of dollars.

At Clutch, Canada's first 100% online pre-owned vehicle retainer, we put all our pre-owned vehicles through a rigorous 210-point inspection that includes checking the tread life on the tires. If they need replacing, we replace them before offering the vehicle for sale.

On top of this, we also inspect the entire vehicle to ensure it's in top shape for you and back it up with a 90-day or 6,000-km warranty. Plus, you get a 10-day or 750-km test-own period. If you don't love your Clutch vehicle during this time, return it for a full refund or exchange it for another vehicle.