Anatomy of a Tire

Tires are made up of several different components*:

The Bead: A rubber-coated loop of high-strength steel cable that allows a tire to stay "seated" on a rim.

The Sidewall: Literally the "side wall" of the tire, this protects cord plies and features tire markings and information like tire size and type.

The Tread: This is where rubber meets road, providing strength, stability and above all else, traction to the road surface.

The Body: This is the tire itself, made up of several layers of plies. Plies, like polyester cord, run perpendicular to the tire's tread and are coated with rubber to help bond with other plies and belts to seal in air. Plies give tires strength and resistance to road damage.

Belts: Rubber coated layers of steel, fiberglass, rayon and other materials located between the tread and plies, criss-crossing at angles hold the plies in place. Belts provide resistance to punctures and help treads stay flat and in contact with the road.

The Inner Liner: This is the innermost layer of a tubeless tire that prevents air from penetrating through the tire.

Sipes: Sipes are special treads within the tread that improve traction on wet, dirty, sandy or snowy road surfaces.

* Beads? Sipes? You can familiarize yourself with Tire Terminology here

Types of Tires

Like vehicles, not all tires are built the same. Depending upon what you drive and when, tires are designed specifically to respond to weather, vehicle size and vehicle function. This aside, one of the best ways to select a tire for your vehicle is to understand tire specification markings where to find them and what they mean.

Summer Tires

Designed primarily for dry and some wet driving, summer tires are not built to perform well on snow and ice, or in cold temperatures. Summer tires are designed for hotter weather, providing maximum traction and resilience on the road.

Summer tire tread design ranges from orbital grooves, to complex directional patterns, promoting various levels of handling in summer driving conditions. Not sure which summer tire is right for your vehicle? Consider the following:

• What is my driving style? (aggressive, relaxed, etc.)
• What am I driving? (minivan, sports sedan, coupe etc.)
• What do I use my vehicle for? (long commutes, weekend shopping, etc.)

For most vehicles, the original tire size is a good guide in choosing new summer tires. However, you should take into account that the larger and wider the tire, the increased likelihood of hydroplaning . To help prevent this, choose a summer tire with directional tread design.

Tire Tip!
Manufacturers provide detailed specifications on each replacement tire, making tire selection easier.

Winter Tires

The need for winter tires has been around for as long as vehicles have, however, with the advent of "all-season" tires, many drivers are unaware of the benefits of winter tires. Designed to provide effective traction in difficult winter conditions like snow, ice and sleet, winter tires feature a combination of specialized tread design and compounds that provides more effective traction in Canada's difficult winter conditions.

Selecting the right winter tires for your vehicle should be based on your driving style and purpose of your vehicle. It is important to learn how to read a tire's side-wall markings to be sure you choose the best winter tires for your vehicle. Having the right winter tires on your vehicle will offer optimal control and traction, while helping to maintain the vehicle's fuel-efficiency.

Other suggestions for choosing winter tires:

• Select a narrow winter tire: wider tires "plow" through snow.
• Determine the "Optional Winter Tire/Wheel Size" from your vehicle's base model. This means taking the base model equivalent of your vehicle and using its tire size as your winter tire template.
• Speak to your GM Goodwrench technician about winter rims.

Performance-wise, two important aspects of winter tires to consider are their speed rating and pressure rating. Most winter tires feature a Q-speed rating, which is lower than general use tires. Winter tires also have specific tire pressure requirements: colder weather will cause tire pressure to decrease, so it is crucial to check your tire pressure in winter more often than you do in summer. Check your owner's manual for the proper pressure for your vehicle's tires.

Tire Tip!
If the tire is not marked with the "Mountain Snowflake Symbol", it is not an approved winter tire.

All-Season Tires

Perhaps the most economical type of tire is the "all-season" tire, because it is designed for year round use. All-season tires feature a blend of technologies that make use of different compounds and detailed tread configurations, designed for most driving conditions like snow, rain, heat, cold etc. It's the "almost" perfect tire because it offers a smooth, quiet ride, with exceptional handling in many conditions.

All season performance does not mean best performance, however. The trade-off is a loss of traction and compound stiffening anywhere below 10 degrees Celsius (50 F). Also, while all-season tires offer greater highway ride comfort, they are not as effective on snow as dedicated winter tires.

All-season tires come in two classes: Passenger Tires and Touring Tires. Passenger Tires feature a smoother ride and longer tread-life while Touring Tires offer low noise and enhanced handling characteristics.

Selecting the right all-season tire for your vehicle should be based on the climate as well as your driving profile. Manufacturers also make the selection process easier. Most all-season tires are branded M+S (Mud + Snow) on the sidewall. Others may feature Four Seasons icons.

Tire Tip!
All-season tires are not designed for generally colder and snowier climates. In such areas, winter tires are recommended.

Performance Tires

Once reserved for exotic sports cars with high horsepower engines, performance tires are now used in practically every type of vehicle, They are available in all shapes and sizes as well as for almost every category and for most conditions, like snow, cold and even dirt roads.

There are four main types of performance tires:

• Performance: Designed for drivers wanting to enhance the look and low-speed traction of their vehicles.
• High-Performance: Designed to enhance high-speed handling and stability.
• Ultra High-Performance: Designed for extreme performance and one of the fastest tires available on today's most sophisticated sports cars and sedans.
• Competition: Built for racing classifications. These tires, while street legal, are impractical for most users because of their racing compounds and groove-free design.

Performance tires offer drivers an overall increase in handling, cornering ability and traction, superior to their original equipment tires. Generally, treads are much shallower than summer, winter or all-season tires, and feature a greater contact patch on the road.

Tire Tip!
Always consult the manufacturer's specifications and guidelines on performance tire use.

Truck Tires

Today's truck tire is available in several categories, each with its own set of performance specifications, depending on truck type:

• Utility: Features excellent wear characteristics and a staggered tread pattern for excellent snow and mud traction for on and off-road use.
• All-Terrain: Features multiple tread pattern, durable compound, and is Rubber Association of Canada (RAC) Snowflake approved.
• Highway Use: An all-season performer with enhanced compounds designed for smoother rides.
• Performance: Optimized for improved performance at higher speeds and better handling, braking and traction in all conditions.
• Off-Road: The most aggressive tread-design, built to power through mud, snow and silt.

Replacing tires on your truck is no more complicated than replacing those of a passenger vehicle. There are two factors, however, that you need to consider: load rating and tire pressure. Because of the larger and heavier workhorse nature of most trucks, these two areas become important points to consider. To verify maximum payload and tire replacement load ratings, always refer to your vehicle's specifications, not the tire's.

Tire Tip!
Overloading a truck tire can cause excessive heat buildup, leading to tire failure.