WHAT YOU NEED TO KNOW

Reading your sidewall
There is a lot of important information moulded into the sidewall of your tire. Check out the graphic below to find out what it all means.

Speed Ratings

Speed Rating	Maximum Speed	Speed Rating	Maximum Speed
B	50 km/h (31 mph)	P	150 km/h (93 mph)
C	60 km/h (37 mph)	Q	160 km/h (99 mph)
D	65 km/h (40 mph)	R	170 km/h (106 mph)
E	70 km/h (43 mph)	S	180 km/h (112 mph)
F	80 km/h (50 mph)	T	190 km/h (118 mph)
G	90 km/h (56 mph)	U	200 km/h (124 mph)
J	100 km/h (62 mph)	H	210 km/h (130 mph)
K	110 km/h (68 mph)	V	240 km/h (150 mph)
L	120 km/h (75 mph)	W	270 km/h (169 mph)
M	130 km/h (81 mph)	Y	300 km/h (188 mph)
N	140 km/h (87 mph)	Z	240+ km/h (149 mph)

Aspect Ratio
This is the relationship of the section-height of a tire to its section-width. It's expressed as a percentage. A section-height that is only 55 or 60% of the section width would present a wider, lower cross-section. This would provide a broader 'footprint' of tread on the road but result in a lower, stiffer sidewall -- better dry traction and handling response but a firmer ride. Conversely, an aspect ratio of 70 or 75 would provide a higher profile with a smoother, softer ride but less handling performance.

Plus Sizing
It is possible -- though not always -- to obtain handling improvements by increasing tire width. Increasing wheel rim diameter and reducing the sidewall height to retain the original diameter can achieve this effect. It results in a wider 'footprint' for improved handling and traction but leaves overall gearing, speedometer and odometer drives unaffected. It is essential that skilled technicians carry out this work, as wheel clearances, suspension operation, load-ratings and turning circles can be seriously affected.

It is vital that the replacement tire have an equal or greater load carrying capacity than the Original Equipment tire and that the overall diameter of the tire/rim of the 'plus-assembly' be nearly the same as the original in order that gear ratios and speedometer readings remain accurate.

P-metric and Euro-Metric
P-Metric sizing is simply the North American way of designating a metric sizing system. The 'P' stands for passenger. European tires of equivalent sizes would drop the prefix 'P' and are otherwise similarly coded. There are slight differences in load capacities and maximum inflation pressures between the two types. Always follow vehicle manufacturer's recommendations.

Construction
Radials: This the most popular form of construction worldwide. Plies are arranged 'radially' or running across the tread at right angles to the circumferential centre-line. Belts placed over the plies provide for a firm, broad 'footprint' while allowing sidewall to flex.

Never mix radials with any other form of tire construction on your vehicle.

Bias or Diagonal-ply: Now rarely used on modern vehicles the cross-ply is found mainly on classic and antique vehicles for reasons of authenticity and sizing. Plies run diagonally in criss-crossing layers across the tire.

Bias-belted: This is essentially a bias-ply construction with encasing, circumferential belts.

Tire Types
All Season Tires: Designated M & S (mud and snow). And may carry S, T or no speed rating. These tires cannot match the steering response of Touring or Performance tires but do provide - for a reasonable price - a smooth, quiet ride and predictable handling. Designed for balanced performance in all weathers - wet, dry and snowy conditions.

Standard Touring Tires: Designated M & S (mud and snow). And are S, T, H or V speed-rated. These tires, in 60, 65,70 and 75 series aspect ratios, offer improved handling and the look of performance tires but with the smooth, quiet ride better suited to passenger cars. Because Standard Touring tires set greater importance on ride comfort and treadwear than Grand Touring tires they tend to be available in taller aspect ratio sizes with lower speed ratings.

Grand Touring Tires: Designated M & S (mud and snow). And are H, V, or Z speed-rated. Grand Touring tires are frequently installed on new vehicles as original equipment. They have excellent handling capability -- but still providing a smooth ride -- and are designed for higher operating speeds than Standard Touring tires. These tires have low 50, 55, 60 and 65-series aspect ratios.

All Season Performance Tires: M & S-designated with S or T speed rating. Designed to replace standard passenger tires but adding a handsome look with bold, black or white lettering. Expect good response and handling with all-season traction. Available in 55, 60, 65 and 70 series aspect ratios.

M & S-designated with U or H speed rating. 60 series and lower. Designed for traction in light snow conditions. Specially formulated compounds remain flexible in cold weather while computerized tread designs provide good traction and excellent handling in all weathers.

Winter Tires: Aggressive tread patterns are designed for outstanding traction in snow and ice. Tread compounds are usually somewhat 'stickier' than found on All-season or Performance tires. Tend to wear faster than All-season tires when used in warm, dry conditions due to increased siping in the tread patterns.

Light Truck & SUV Highway Rib Tires: Developed primarily for the highway. Straight, circumferential rib design provides consistent, even wear, low noise and a pleasing, smooth ride.

Light Truck & SUV Highway All-Season Tires: Small tread-blocks provide the ride qualities of a passenger tire for the highway but provide, also, traction on gravel, sand and moderate snow.

Light Truck & SUV Off-Road, All-Terrain Tires: Designed for competent highway performance with off-road capability. Multi-faceted tread blocks provide 'bite' against front and sideways forces and will perform well on gravel, sand, mud and snow. Tend to be somewhat noisier and harsher than highway tires.

Tread depth
Tires must be replaced when the treadwear indicators (they look like narrow bars of rubber) become visible. These narrow bars of rubber indicate that the tread is depth is down to 1/16"^*

When wear bars are visible, the tire is worn out and must be replaced.

*This might be expressed as 2/32". 32nds of an inch are the industry standard for tread depth measurement)

UTQGS
Uniform Tire Quality Grade System: This is a coding that is required by the US government. Tire manufacturers assign values for Treadwear, Traction and Temperature performance. The standards were originally devised and supervised by the US government and intended to help customers make choices between various types of tire. In recent years, however, government involvement has declined and manufacturers have each been conducting their own tests independently. This clearly makes comparisons between brands unreliable. Values are still useful for relative comparisons within a given manufacturer's tire line, though.

The Treadwear Rating: The standard rating selected by the government was set at 100 but today all passenger tires easily exceed this. A tire rated at 200 would be expected to last twice as long on the set course as one rated at 100. Treadwear ratings do not apply to Winter, Light Truck or 12" tires.

The Traction Rating: This measures the tires ability to stop on wet pavement under controlled conditions on specified government test surfaces of asphalt and concrete. The traction grade is based upon "straight ahead" braking tests. It does not indicate cornering ability. Letters are used to represent this rating - AA being the highest then grading down through A, B and C. Traction grading is more a measure of tread-compound 'stickiness' and less for tread-design.

The Temperature Rating: Letters are also used to represent this rating. It's a measure of how well a tire can resist the build-up of heat and its ability to dissipate it. C is the minimum rating for passenger tires. Tires which rate A or B will perform above the minimum set by the US government.

TIRE MAINTENANCE

Balancing
Tires should be balanced to ensure vibration-free ride and to avoid damage to steering and suspension components. Computerized, dynamic balancing corrects uneven weight displacement in wheel and tire assemblies. Your Canadian Tire Auto Service Centre is outfitted with the latest, most up-to-date wheel-balancing equipment.

Alignment
Nobody would knowingly drag their car tires sideways. But, in effect, this is exactly what happens when wheels are out of alignment! Misalignment of just 0.5° is equivalent to dragging a tire sideways 8.7 metres for every kilometre traveled!

Inspect your tires. Any feathering of the tread face, apparent to eye or touch, is a reliable sign of misalignment or worn suspension.

Avoid curb scuffing - it's a frequent cause of wheel misalignment.

2-wheel or 4-wheel alignment? All four wheels should be properly aligned. It's particularly important to check 4-wheel alignment on FWD vehicles because they lack a rear drive axle, which tends to keep rear wheels in alignment.

Inflation
The most frequent cause of radial tire failure is under-inflation! Even extreme under-inflation can be difficult to detect by mere inspection - don't depend on it, use a personal tire pressure gauge.

Under inflated or overloaded tires, generate high levels of destructive, internal heat, which could, eventually, cause your tires to blow out! Extreme under-inflation can even unseat the tire from the rim while your vehicle is in motion!

Check tire pressures at least twice a month -- especially after sudden temperature changes. Tire inflation pressure drops 1psi for every 5.5°C drop in outside temperature. Check inflation when tires are COLD: when the vehicle has been driven less than 2km.

Correct air pressure ensures longer tire life, improved economy and lower risk of accident.

Check your owner's manual for the recommendations for your vehicle. They can also be found labeled on door edge or post, glove box or fuel filler doors.

If a tire frequently needs air, have it checked at your Canadian Tire Auto Service Centre.

Inspect your tires frequently. Remove stones, glass and other objects from the tread before they damage the tire and result in air loss.

Purchase and use your own tire pressure gauge. It is the single most effective way of ensuring consistne accuracy of inflation

Tire care tips:

• Maintain proper tire inflation as recommended by your vehicle's manufacturer. Check tires twice monthly with a good quality tire gauge when tires are cool.
• Rotate tires every 8-10,000 km or based on vehicle manufacturer's recommendations or at first sign of irregular wear.
• Do not exceed the maximum load-carrying capability of your tires. (see How To Read Your Sidewall)
• Check tires for scrapes, bulges, separations or cuts
• Respect speed limits and adjust speed to driving conditions
• Avoid curb-scuffing or running over objects that may damage your tires

Tires On Demand
In addition to our assortment of regularly-stocked tires, we carry brand name tires by MICHELIN, GOODYEAR, BFGOODRICH, UNIROYAL and DUNLOP. Whether you drive a car, light truck or SUV in city, highway or off-road conditions, we can get the tire you need without delay. Start by browsing through our vast selection on our website. Once you find what you want, simply call or visit your nearest Canadian Tire Auto Service Centre. The professionals there will place the order for you directly from the manufacturer and before you know it, you'll be driving on your brand new tires! What's more, our coast-to-coast Customer Care Program covers every Tires on Demand Tire we sell so you have complete peace of mind. For even greater comfort, ask about our Protection Plan PLUS.

Tire Rotation
To prevent uneven wear, Canadian Tire recommends tire rotation at 10,000 km intervals or whenever you see signs of uneven tire wear beginning. Rotation equalizes wear between tires mounted on driver wheels and those on free-rolling positions.

ABOUT RIMS

Offset
The offset of a wheel is the distance from the mounting surface of the wheel to the true centerline of the rim. A positive offset means the mounting surface of the wheel is positioned in front of the true centerline of the rim / tire assembly. This in effect brings the tire in to the fender-well more. Conversely, a negative offset means the mounting surface of the wheel is behind the true centerline of the rim / tire assembly. This will cause the tire to stick out away from the vehicle.

Bolt Patterns
Each wheel has a different bolt pattern, and some wheels even have 2 different bolt patterns, which allow it to be mounted on a wider range of vehicles.

Most Bolt Patterns are represented in the following manner:

4/100

• The "4" indicates the number of holes in the wheel for the bolts to enter and mount the wheel onto the car.
  
• The "100" indicates the diameter of the bolt circle measured in millimeters or inches. 4 & 6 bolt wheels are measured from the center of one bolthole to the center of the bolthole directly across from it. On a 5-bolt pattern, it is a bit trickier to measure without special tools. Imagine a circle running through the centers of each bolthole. You would measure from the center of one bolthole to the imaginary circle that lies between the opposite two boltholes.

Plus Sizing
Plus sizing your wheel & tire combination was designed to enhance vehicle performance and aesthetics by allowing fitment of larger diameter rims and lower profile tires. The theory is that while making these changes, you keep the overall tire diameter within 3% of the original equipment tires. This is important because larger variances can cause problems with transmission shift points, which can decrease fuel mileage. It can also confuse braking system computers, which can even lead to brake failure.

Here's the rule of thumb for "plus sizing":

Plus 1:
Increase section width by 10mm
Decrease aspect ratio by 10 points
Increase rim diameter by 1 inch

Plus 2:
Increase section width by 20mm
Decrease aspect ratio by 20 point
Increase rim diameter by 2 inches.

This is not exact, but it will usually get you in the right ballpark. We always recommend consulting with the people you are purchasing the wheels and tires from to ensure fitment.

Wheel Care
It is important to keep your wheels clean at all times. Your brakes will cause the wheels to heat up, and this heat in turn can cause any dirt or brake dust to cook in to the clear coat. If this happens, there's not a lot you can do besides having the wheels refinished. Protect your investment and keep your wheels clean!

Below are some simple instructions on how to take care of your wheels:

• Do not use household cleaners or other detergents to clean your wheels. The best wheel cleaning solution is a mild soap and water solution (what ever you would trust on the paint of your car). Clean with a soft, un-abrasive cloth. Only on polished wheels can you use aluminum wheel polish. If you use this polish on chrome, painted, or clear coated wheels, you will only scratch or dull the finish.
• Do not use steam cleaners in automatic car washes.
• Do not use any tire cleaners on your wheels.
• Clean wheels when they are cool. Heat can effect the soap, causing it to dry on the wheel and become difficult to rinse off.
• Clean one wheel at a time. This also prevents the soap from drying on to the wheel.
• After the wheels are clean and dry, apply a coat of soft paste style wax to them. This will create a moisture barrier and help ensure the finish lasts as long as possible.

Centerbore
This relates to the center hole in the wheel that centers the wheel on the hub of the car. Since most wheels are mass-produced, they have a large center bore to accommodate several different vehicles. If this is the case, it is recommended that you use a hub ring.

Hub rings are hard plastic or metal rings that fits between the wheel and the vehicle. This centers the wheel perfectly on the hub ensuring that there is no run out when the wheel is installed on to the vehicle. Without hub rings it is possible to get vibrations even if the wheel / tire assembly is perfectly balanced.

Torque
All alloy wheels should be installed using a torque wrench. This ensures that the wheels are not too tight or too loose. Check your vehicle's manual for correct settings. When you install wheels for the first time, you should re-torque wheels after about 100km to 150km (60 to 90 miles).

Alloy vs. Steel
The main differences between alloy and steel wheels lie in their durability and strength. Most high-performance wheels are made of an alloy and composed of aluminum, and other metallic substances. By using alloy wheels, you not only improve the looks of your vehicle but also the performance. The extra strength provides longevity as well as effecting tire wear in a positive manner. The weight reduction will improve steering response and handling, as well as help improve acceleration and braking.

Wheel Construction
There is a good variety of ways of constructing wheels. Most alloy wheels are made in one, two or three piece construction types.

One piece is just what it says, a wheel made in a mold as a single piece.

Two piece wheels are made of two separate pieces (center and barrel) that are usually welded or bolted together.

Three-piece wheels are made of three separate pieces. They have a center, and inside rim half, and an outside rim half. They are bolted together using the highest quality fasteners.

Manufacturing method is very important in the overall quality and performance of a wheel. Here are the most common types of manufacturing techniques employed:

Forging
Considered to be the best manufacturing technique, forging allows for the compression of an aluminum billet (one solid piece of aluminum) into an aluminum wheel using over 13 million pounds of pressure combined with heat. This produces a wheel that is both stronger and lighter then your standard aluminum wheel.

A subset of forging is called roll forging. In this process, a metal blank is run through rollers with impressions sunk in to their surface giving the wheel its final shape. This allows the wheel to be produced with less aluminum, reducing weight but maintaining strength.

Low Pressure Casting
This is the most common form of rim manufacturing. Much like a casting, liquid metal is poured into a mold and allowed to harden until the finished wheel is cool enough to be taken out of the casting.

Counter Pressure
Casting Opposite to low-pressure casting, the liquid metal is not poured, rather it is sucked into the mold using a vacuum. This reduces impurities making the wheel much stronger than a low pressure cast rim.

Hardware
The hardware holding your wheels to your car is an often-overlooked step when installing new rims. Most aftermarket wheels require different wheel nuts / bolts than what was used on the original equipment wheels.

Wheel nuts and bolts have many different seats (where the nut touches the wheel). The 3 most common are acorn seat (conical), ball seat (radius), and mag shank seat. These differences along with different lengths and diameters makes hardware very confusing.

Always check with the people who supplied your wheels for the correct mounting hardware before trying to install them on your vehicle.