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If you haven't purchased new tires before, the prospect can seem challenging. With so many things to consider, it may be hard to know where to begin. This guide will outline all of the essentials – from understanding the most basic differences between all season, performance and winter tires to reading your tire sidewall information to ensure that you purchase the right size and type of tires for your vehicle.
Tire Differences
All Season Tires
As the name suggests, all season tires are designed to provide safe driving over a wide range of conditions. The advantage to all season tires is that they can remain on your vehicle spring, summer and fall, but may not be suitable in cold temperatures or snowy weather. They also provide a quieter ride than winter tires.
Performance Tires
Dedicated summer tires will improve the performance and aesthetics of your vehicle. Performance tires are designed for handling and stability, which can result in a stiffer tire. This may affect the comfort of your ride. The tread is also wider to provide more contact with the road and better dry traction. The special compound used enhances performance but may not provide the same tread wear as all season tires.
Winter Tires
Winter tires use special compounds to improve your traction, stopping and handling whenever the thermometer dips below 7°C/45°F. Although all weather tires are good in many conditions, they don't provide the same grip and control that winter tires can in cold or snowy weather.
Tire Sidewall Information
On the sidewall of every tire, there's a great deal of information that identifies its construction and capabilities.
Example: P185/75R14 82S
PService type: Indicates this is a passenger vehicle tire, as opposed to a tire made for a light truck (LT) or other vehicle.185Section Width: The width of the tire in millimetres from sidewall to sidewall. This measurement varies depending on the width of the rim to which the tire is fitted: larger on a wider rim, smaller on a narrow rim. The number on the side of the tire indicates the width measured with the tire fitted to the recommended rim width.75Aspect Ratio: The ratio of height to width. This tire's height is 75% of its width.RInternal Construction: How the plies are constructed in the tire carcass. "R" means radial. "B" in place of the "R" means the tire is belted bias construction. "D" in place of the "R" means diagonal bias construction.14Rim Diameter: The diameter of the wheel in inches.82Load Index: This tire has an industry-standard maximum load of 475 kg (1,047 lbs.) Different load index numbers correspond to different maximum loads. The maximum load is shown in lbs. (pounds) and in kg (kilograms), and maximum pressure in PSI (pounds per square inch) and in kPa (kilopascals).SSpeed Rating: This tire has an industry-standard maximum service speed of 130 mph. Different letters correspond to different maximum service speeds.
Here are some other markings to look for on your tire's sidewall:
The mountain/snowflake symbol indicates a Severe Snow Conditions rating—the safest tires for any kind of winter driving. These tires have been designed specifically for use in cold weather and severe snow conditions, and have been performance tested as meeting or exceeding industry established snow traction performance requirements. See our Winter Tires Guide for complete details.
The M+S (also displayed as M&S or M-S) indicates the tire has all-season capabilities. Tires bearing this mark offer great traction and can be used in rain, snow, and muddy conditions. This designation indicates a specified tread-to-void ratio; however it does not mean that the tire has passed any road tests ensuring effectiveness in severe winter conditions.
All the winter tires sold at Canadian Tire will accept winter studs. Note that there are different provincial rules and regulations for the use of studded tires.Maximum Inflation Pressure is the highest inflation pressure that the tire can withstand. This is not, however, the recommended inflation pressure. Inflation pressures should never be below the pressure recommended by your vehicle manufacturer or above the maximum pressure branded on the tire's sidewall.
Tire & Sidewall Glossary
Tire Tread - The flat area of the tire that contacts the road surface. A tire's tread construction determines the adhesion characteristics of the tire in all driving conditions.
Tire Bead - The narrow band that anchors the tire to the rim and maintains a leak-free seal. This area transmits acceleration, turning, braking and all other forces between the vehicle and the road.
Tire Sidewall - The vertical portion of the tire that extends from the road surface to the bead. Sidewall construction and depth affects the ride and handling of the tire. A narrow, stiff sidewall offers more responsive steering, but a deep, supple sidewall will flex to provide a smoother ride.
Tire Shoulder - The curved region where the vertical sidewall of the tire meets the horizontal tread.
Construction Materials
Branding on the sidewall of tires lists the materials and number of layers of each material used to reinforce the rubber. Here's an example of how a typical tire's basic construction materials are usually presented:
TREAD 2 POLYESTER + 2 STEEL + 1 NYLONSIDEWALL 2 POLYESTER
In this example, the branding indicates that moulded into the rubber under the centerline of the tread lies:
It also identifies that in each sidewall lies two radial body plies of polyester cord (a continuation of the same two radial body plies that were listed under the centerline of the tread).
Some construction information may not be indicated in the branding for tires.
Tire Sidewall Descriptions
In addition to the construction branding and ratings, tire sidewalls can include stripes, bands or lettering that give a tire a distinctive look. Below is a quick legend of notations used for describing the appearance of a tire's sidewall.
Sidewall MarkingMeaningBCSBlack Circumferential SerrationBLBlack LettersBSLBlack Serrated LettersBSBBroken Serrated BandENWLExtra Narrow White LettersROBLRaised Outlined Black LettersOWLOutlined White LettersOBLOutlined Black LettersOGLOutlined Gold LettersORBLOutlined Raised Black LettersORWLOutlined Raised White LettersOWLOutlined White LettersRBLRaised Black LettersRWLRaised White LettersRRBLRecessed Raised Black LettersSBLSerrated Black LettersSRBLSerrated Raised Black LettersSOWLSlanted Outlined White LettersSVSBSlanted Vertical Serrated BandVSBVertical Serrated BandWLWhite LettersWSWhite StripeWWWhite Wall
Tire Size
The tire size branded on the sidewall provides a significant amount of information about the tire's intended purpose, dimensions, load capacity and high temperature/high speed durability.
Our primary example will be based on variations of P185/75R14 82S, although other sizes will appear where appropriate.
Service Type
Most tire sizes begin with one or two letters that identify the type of vehicle or type of service they were designed for. Here are some of the most common indicators:
Section Width
The three-digit numeric portion following the service type designation identifies the tire's Section Width (cross section) in millimetres.
You can convert the section width measurement to inches by dividing the measurement by 25.4.
Typically following the three digits identifying the tire's Section Width is a two-digit number that identifies the tire's aspect ratio or profile. A lower profile tire will have a shallower sidewall, providing enhanced handling and responsiveness.
We know that this tire size's section width is 185 mm and that its section height is 75% of 185 mm. By converting the 185 mm to inches (185 / 25.4 = 7.28") and multiplying it by 75% (.75) we can determine that tire section height is 5.46".
Internal Construction
Following the two digits to indicate aspect ratio, a letter is used to identify the tire's internal construction.
If there was a B in place of the R (P185/75B14), it would indicate the tire features belted bias construction.
If the R in the size was replaced with a D (P185/75D14), it would identify that the internal tire body plies crisscross on a Diagonal and that the tire has a "bias ply" construction. Tires using this construction are used for light truck and spare tire applications.
Diameter of Wheels and Tires
Following the internal construction, a number indicates the bead of the tire, and the required wheel size.
Most commonly, tires express the rim diameter in whole inches ranging from 8 to 28. While not as common, two additional "unique" types of tire/wheel diameters are still in use today.
Some heavy-duty trailers, heavy-duty light trucks and box vans have a tire and wheel rim diameter expressed in "half" inches (8.00R16.5LT, as well as, 14.5, 15.5, 17.5 and 19.5).
Some integrated wheel/tire systems are in use on a very limited basis as Original Equipment in North America. These systems feature "asymmetric" beads in which the outside bead and inside bead are actually different diameters.
Wheels and tires with unique rim diameters should never be combined with traditional "inch rim" wheels and tires. These unique tire/wheel diameters feature bead profiles that have a different shape than traditional "inch rim" sizes, and were developed specifically because their application required them to be different than conventional wheels and tires.
Always confirm tire and wheel diameters match before mounting the tire on the wheel.
Load Index & Tire Speed Ratings
Following the tire and wheel diameter, two numbers and a letter indicate the Load Index and Tire Speed Ratings, also known as its Service Description.
P185/75R14 82S
82 indicates the Load Index and S indicates the Speed Rating.
Load Index
P185/75R14 82S - The load index (82 in this example) indicates the tire's relative load carrying capabilities. The numbers correspond to a set index, with higher numbers indicating the ability to carry a heavier load. Our example, 82, indicates the tire can carry about 475 kg (1,047 lbs.)
Typical load indexes for tires used on passenger cars and light trucks range from 70 to 110.
Load IndexPoundsKilogramsLoad IndexPoundsKilograms71761345911,35661572783355921,38963073805365931,43365074827375941,47767075853387951,52169076882400961,56571077908412971,60973078937425981,65375079963437991,709775809924501001,764800811,0194621011,819825821,0474751021,874850831,0744871031,929875841,1025001041,984900851,1355151052,039925861,1685301062,094950871,2015451072,149975881,2355601082,2051,000891,2795801092,2711,030901,3236001102,3371,060
Tire Speed Rating
P185/75R14 82S - The speed rating (S in this example) indicates the maximum service speed of which the tire is capable. The letter corresponds to a set index; with a few exceptions (ex.: H, Z) letters which appear later in the alphabet indicate the ability to travel at a higher speed. Our example, S, indicates the tire can safely operate at speeds of up to 180 km/h (112 mph)
Speed Rating MaximumSpeedB50 km/h (31 mph)C60 km/h (37 mph)D65 km/h (40 mph)E70 km/h (43 mph)F80 km/h (50 mph)G90 km/h (56 mph)H210 km/h (130 mph)J100 km/h (62 mph)K110 km/h (68 mph)L120 km/h (75 mph)M130 km/h (81 mph)N140 km/h (87 mph)P150 km/h (93 mph)Q160 km/h (99 mph)R170 km/h (106 mph)S180 km/h (112 mph)T190 km/h (118 mph)U200 km/h (124 mph)V240 km/h (150 mph)W270 km/h (169 mph)Y300 km/h (188 mph)Z240+ km/h (149 mph)
Load Range & Ply Rating Identification
Tires are engineered to withstand a maximum load and inflation pressure. These maximums for tires are branded on the sidewall of all tires sold in North America. Passenger vehicles specify the load ranges while light trucks use letter-indicated load ranges that ascend in alphabetical order.
Prior to using load ranges, ply ratings were used, indicating the relative strength of tires by identifying the actual number of plies used in the tire's construction. Because tire construction has changed over the years, load ratings were developed to indicate the equivalent strength as compared to early bias ply tires.
In our example of the P185/75R14 82S tire, its maximum load and maximum tire inflation pressure typically presented on the sidewall as follows:
Tire pressures are most commonly measured in psi—pounds per square inch, Kilopascals (kPa) or bars of pressure (bars).
Tire Differences
All Season Tires
As the name suggests, all season tires are designed to provide safe driving over a wide range of conditions. The advantage to all season tires is that they can remain on your vehicle spring, summer and fall, but may not be suitable in cold temperatures or snowy weather. They also provide a quieter ride than winter tires.
Performance Tires
Dedicated summer tires will improve the performance and aesthetics of your vehicle. Performance tires are designed for handling and stability, which can result in a stiffer tire. This may affect the comfort of your ride. The tread is also wider to provide more contact with the road and better dry traction. The special compound used enhances performance but may not provide the same tread wear as all season tires.
Winter Tires
Winter tires use special compounds to improve your traction, stopping and handling whenever the thermometer dips below 7°C/45°F. Although all weather tires are good in many conditions, they don't provide the same grip and control that winter tires can in cold or snowy weather.
Tire Sidewall Information
On the sidewall of every tire, there's a great deal of information that identifies its construction and capabilities.

PService type: Indicates this is a passenger vehicle tire, as opposed to a tire made for a light truck (LT) or other vehicle.185Section Width: The width of the tire in millimetres from sidewall to sidewall. This measurement varies depending on the width of the rim to which the tire is fitted: larger on a wider rim, smaller on a narrow rim. The number on the side of the tire indicates the width measured with the tire fitted to the recommended rim width.75Aspect Ratio: The ratio of height to width. This tire's height is 75% of its width.RInternal Construction: How the plies are constructed in the tire carcass. "R" means radial. "B" in place of the "R" means the tire is belted bias construction. "D" in place of the "R" means diagonal bias construction.14Rim Diameter: The diameter of the wheel in inches.82Load Index: This tire has an industry-standard maximum load of 475 kg (1,047 lbs.) Different load index numbers correspond to different maximum loads. The maximum load is shown in lbs. (pounds) and in kg (kilograms), and maximum pressure in PSI (pounds per square inch) and in kPa (kilopascals).SSpeed Rating: This tire has an industry-standard maximum service speed of 130 mph. Different letters correspond to different maximum service speeds.
Here are some other markings to look for on your tire's sidewall:



Tire & Sidewall Glossary
Tire Tread - The flat area of the tire that contacts the road surface. A tire's tread construction determines the adhesion characteristics of the tire in all driving conditions.
Tire Bead - The narrow band that anchors the tire to the rim and maintains a leak-free seal. This area transmits acceleration, turning, braking and all other forces between the vehicle and the road.
Tire Sidewall - The vertical portion of the tire that extends from the road surface to the bead. Sidewall construction and depth affects the ride and handling of the tire. A narrow, stiff sidewall offers more responsive steering, but a deep, supple sidewall will flex to provide a smoother ride.
Tire Shoulder - The curved region where the vertical sidewall of the tire meets the horizontal tread.
Construction Materials
Branding on the sidewall of tires lists the materials and number of layers of each material used to reinforce the rubber. Here's an example of how a typical tire's basic construction materials are usually presented:
TREAD 2 POLYESTER + 2 STEEL + 1 NYLONSIDEWALL 2 POLYESTER
In this example, the branding indicates that moulded into the rubber under the centerline of the tread lies:
- two radial body plies of polyester cord
- two belts of angled steel cord
- one circumferential cap ply of nylon cord.
It also identifies that in each sidewall lies two radial body plies of polyester cord (a continuation of the same two radial body plies that were listed under the centerline of the tread).
Some construction information may not be indicated in the branding for tires.
- Many high-speed tires are constructed with circumferential reinforcements above the steel belts. These belt edge strips or full cap plies are not under the centerline of the tread, so this information won't be indicated in the branding for the tread area.
- Ultra high performance tires may also use fabric or steel cord reinforced sidewalls to increase steering response and cornering stability. However, since this sidewall-reinforcing material is not present at the widest points of the tire's sidewalls, this information won't be indicated in the branding for the sidewall area.
Tire Sidewall Descriptions
In addition to the construction branding and ratings, tire sidewalls can include stripes, bands or lettering that give a tire a distinctive look. Below is a quick legend of notations used for describing the appearance of a tire's sidewall.
Sidewall MarkingMeaningBCSBlack Circumferential SerrationBLBlack LettersBSLBlack Serrated LettersBSBBroken Serrated BandENWLExtra Narrow White LettersROBLRaised Outlined Black LettersOWLOutlined White LettersOBLOutlined Black LettersOGLOutlined Gold LettersORBLOutlined Raised Black LettersORWLOutlined Raised White LettersOWLOutlined White LettersRBLRaised Black LettersRWLRaised White LettersRRBLRecessed Raised Black LettersSBLSerrated Black LettersSRBLSerrated Raised Black LettersSOWLSlanted Outlined White LettersSVSBSlanted Vertical Serrated BandVSBVertical Serrated BandWLWhite LettersWSWhite StripeWWWhite Wall
Tire Size
The tire size branded on the sidewall provides a significant amount of information about the tire's intended purpose, dimensions, load capacity and high temperature/high speed durability.
Our primary example will be based on variations of P185/75R14 82S, although other sizes will appear where appropriate.
Service Type
Most tire sizes begin with one or two letters that identify the type of vehicle or type of service they were designed for. Here are some of the most common indicators:
P185/75R14 82S
P = Tire sizes that begin with a P indicate the tire is a P-metric size. These tires are designed for passenger vehicles such as cars, minivans, SUVs and light duty pickup trucks.185/75R14 82S
If there isn't a letter preceding the three-digit numeric portion of a tire size, it signifies the tire is a Euro-Metric size, sometimes just referred to as Metric. Euro-metric sizes are dimensionally equivalent to P-metric sizes, but can subtly differ in load carrying capabilities.LT245/75R16 108/104S
LT = Tire sizes beginning with LT indicate Light Truck-metric size tires designed for use on vehicles capable of carrying heavy cargo or towing large trailers. This includes medium and heavy-duty pickup trucks, SUVs and full-size vans.7.50R16LT 112/107Q
8.75R16.5LT 104/100Q
31x10.50R15LT 109Q
LT = If a tire size ends with LT, it indicates the tire is either an earlier Numeric, Wide Base or Flotation Light Truck size. Numeric sizes are designed for use on vehicles that are capable of carrying heavy cargo and towing trailers. Wide Base sizes use 16.5-inch diameter rims. Flotation sizes are wider, oversized tires designed to help the vehicle drive on top of loose dirt or sandy surfaces.8.75R16.5LT 104/100Q
31x10.50R15LT 109Q
Section Width
The three-digit numeric portion following the service type designation identifies the tire's Section Width (cross section) in millimetres.
P185/75R14 82S
This tire is 185 millimetres across from the widest point of its outer sidewall to the widest point of its inner sidewall when mounted and measured on a specified width wheel.You can convert the section width measurement to inches by dividing the measurement by 25.4.
185 mm / 25.4 = 7.28"
Tire Sidewall Aspect RatioTypically following the three digits identifying the tire's Section Width is a two-digit number that identifies the tire's aspect ratio or profile. A lower profile tire will have a shallower sidewall, providing enhanced handling and responsiveness.
P185/75R14 82S
The 75 indicates that this tire size's sidewall height (from rim to tread) is 75% of its section width. The measurement is the tire's section height, and also referred to as the tire's series, profile or aspect ratio. The higher the number, the taller the sidewall; the lower the number, the lower the sidewall.We know that this tire size's section width is 185 mm and that its section height is 75% of 185 mm. By converting the 185 mm to inches (185 / 25.4 = 7.28") and multiplying it by 75% (.75) we can determine that tire section height is 5.46".
Internal Construction
Following the two digits to indicate aspect ratio, a letter is used to identify the tire's internal construction.
P185/75R14 82S
The R size identifies that the tire has a Radial construction, in which the tire's body plies "radiate" out from the imaginary center of the wheel. Radial tires are by far the most popular type of tire today representing over 98% of all tires sold.If there was a B in place of the R (P185/75B14), it would indicate the tire features belted bias construction.
If the R in the size was replaced with a D (P185/75D14), it would identify that the internal tire body plies crisscross on a Diagonal and that the tire has a "bias ply" construction. Tires using this construction are used for light truck and spare tire applications.
Diameter of Wheels and Tires
Following the internal construction, a number indicates the bead of the tire, and the required wheel size.
P185/75R14 82S
The 14 indicates the tire is designed to be installed on 14 inch diameter rims.Most commonly, tires express the rim diameter in whole inches ranging from 8 to 28. While not as common, two additional "unique" types of tire/wheel diameters are still in use today.
Some heavy-duty trailers, heavy-duty light trucks and box vans have a tire and wheel rim diameter expressed in "half" inches (8.00R16.5LT, as well as, 14.5, 15.5, 17.5 and 19.5).
Some integrated wheel/tire systems are in use on a very limited basis as Original Equipment in North America. These systems feature "asymmetric" beads in which the outside bead and inside bead are actually different diameters.
Wheels and tires with unique rim diameters should never be combined with traditional "inch rim" wheels and tires. These unique tire/wheel diameters feature bead profiles that have a different shape than traditional "inch rim" sizes, and were developed specifically because their application required them to be different than conventional wheels and tires.
Always confirm tire and wheel diameters match before mounting the tire on the wheel.
Load Index & Tire Speed Ratings
Following the tire and wheel diameter, two numbers and a letter indicate the Load Index and Tire Speed Ratings, also known as its Service Description.
P185/75R14 82S
82 indicates the Load Index and S indicates the Speed Rating.
Load Index
P185/75R14 82S - The load index (82 in this example) indicates the tire's relative load carrying capabilities. The numbers correspond to a set index, with higher numbers indicating the ability to carry a heavier load. Our example, 82, indicates the tire can carry about 475 kg (1,047 lbs.)
Typical load indexes for tires used on passenger cars and light trucks range from 70 to 110.
Load IndexPoundsKilogramsLoad IndexPoundsKilograms71761345911,35661572783355921,38963073805365931,43365074827375941,47767075853387951,52169076882400961,56571077908412971,60973078937425981,65375079963437991,709775809924501001,764800811,0194621011,819825821,0474751021,874850831,0744871031,929875841,1025001041,984900851,1355151052,039925861,1685301062,094950871,2015451072,149975881,2355601082,2051,000891,2795801092,2711,030901,3236001102,3371,060
Tire Speed Rating
P185/75R14 82S - The speed rating (S in this example) indicates the maximum service speed of which the tire is capable. The letter corresponds to a set index; with a few exceptions (ex.: H, Z) letters which appear later in the alphabet indicate the ability to travel at a higher speed. Our example, S, indicates the tire can safely operate at speeds of up to 180 km/h (112 mph)
Speed Rating MaximumSpeedB50 km/h (31 mph)C60 km/h (37 mph)D65 km/h (40 mph)E70 km/h (43 mph)F80 km/h (50 mph)G90 km/h (56 mph)H210 km/h (130 mph)J100 km/h (62 mph)K110 km/h (68 mph)L120 km/h (75 mph)M130 km/h (81 mph)N140 km/h (87 mph)P150 km/h (93 mph)Q160 km/h (99 mph)R170 km/h (106 mph)S180 km/h (112 mph)T190 km/h (118 mph)U200 km/h (124 mph)V240 km/h (150 mph)W270 km/h (169 mph)Y300 km/h (188 mph)Z240+ km/h (149 mph)
Load Range & Ply Rating Identification
Tires are engineered to withstand a maximum load and inflation pressure. These maximums for tires are branded on the sidewall of all tires sold in North America. Passenger vehicles specify the load ranges while light trucks use letter-indicated load ranges that ascend in alphabetical order.
Prior to using load ranges, ply ratings were used, indicating the relative strength of tires by identifying the actual number of plies used in the tire's construction. Because tire construction has changed over the years, load ratings were developed to indicate the equivalent strength as compared to early bias ply tires.
In our example of the P185/75R14 82S tire, its maximum load and maximum tire inflation pressure typically presented on the sidewall as follows:
MAX. LOAD 2000 kg (4410 lbs)
AT 760 kPs (110 psi) COLD
This branding identifies that the tire in this example must be capable of, and be rated to carry 2000 kg (4,410 pounds), and that the maximum tire inflation pressure for this tire is 300 kPa (44 psi).AT 760 kPs (110 psi) COLD
Tire pressures are most commonly measured in psi—pounds per square inch, Kilopascals (kPa) or bars of pressure (bars).
1 psi = 6.895 kPa = 0.0689 bars
The maximum load rating for the tire is based on industry standard tire load pressures—not the maximum tire pressure specific for the tire.