Tires carry a wealth of information on their sidewalls; unfortunately, it's all in code. Most of it is of no concern to many owners, but it can be valuable for those who want to know the seasons for which their tires are intended, those who plan to replace their tires, or new-car buyers who are given a choice of sizes and types.
Apart from the name of the manufacturer and the tire model -- such as Bridgestone Turanza EL 400 -- the following marking, from a Honda Civic, is likely the most prominent.
P simply means this is a passenger-car tire. Other codes include T (temporary, as in a spare tire), LT (light truck) and C (commercial). Not all tires include this letter.
205 (the first number) is the tire's width in millimeters.
55 (the number following the slash) is a measure of the tire's profile -- the height of its sidewall relative to its width -- expressed as the sidewall's aspect ratio in a percentage. In this example, the sidewall height is 55 percent of the tire's width, which is 205 mm. The number is known as the tire's series; a sporty tire with shorter sidewalls would be considered a lower-series tire. Off-road tires tend to be higher-series, designed to absorb the impact from rough surfaces.
R means it is a radial tire, which describes the way the underlying layers, or plies, are laid out. The radial design is now so pervasive that the R designation is superfluous -- though it conveniently separates the series and diameter numbers. On some performance tires, an additional letter precedes the R: A ZR designation means the tire's maximum speed rating is above 149 mph (see the key below). This is another unnecessary character; all tires provide a letter designation in the service description, explained below. It follows the size code, sometimes in smaller type.
Speed Ratings Letter / Max. MP
N/87
P/93
Q/99
R/106
S/112
T/118
U/124
H/130
V/149
W/168
Y/186
Z*150
*Z is an open-ended rating that means the tire's maximum speed is, at minimum, 150 mph.
16 (the last number) is the diameter, in inches, of the rim on which the tire fits.
89H is the service description. Separated from the main code, it represents the tire's load and speed ratings. This tire's 89 load index represents 1,279 pounds (per tire), and the speed rating of H represents 130 mph. The speed rating is less important in the U.S., where the speed limits are below even the lowest listed rating (N, or 87 mph). In other countries -- and our own, when no one's looking -- people are known to drive 100 mph and above.
M+S stands for mud and snow, indicating that this is an all-season tire. It's not the clearest of the specs, because there aren't other designations for summer and winter tires: Summer tires simply lack the M+S, and winter tires are labeled M+S and add an icon of a mountain plastered with a giant snowflake. (S, AS and W would be better, but what can you do?) Uniform Tire Quality Grade The following three codes, which appear on the sidewall, typically closer to the tire's tread, are part of the National Highway Traffic Safety Administration's uniform tire-quality grading system.
Unfortunately, it's not all that uniform: It appears on all-season and summer tires, but not on snow tires, light-truck tires or spares. Further, the rating comes from the manufacturers, whose results might be consistent from one of their products to the next, but whose universality is questionable.
TREADWEAR 300 TRACTION A TEMPERATURE A
Treadwear: Uses numbers from 100 to about 700. Theoretically, a tire rated 150 would have a 50 percent longer lifespan than a tire rated 100 if used in the same conditions -- driver, vehicle and roads. Soft summer tires tend to have lower treadwear ratings than all-season tires. Winter tires aren't rated, but their soft compounds make for quick wear when driven off snow and ice.
The uniform tire quality grade is located on the sidewall near the tread. Traction: Uses AA, A, B and C, with AA being the best traction on a wet road. The traction measured is straight-line acceleration and braking. This is not a measure of cornering grip or performance on dry surfaces.
Temperature: Uses letter grades A, B and C, with A representing the best resistance to heat buildup and C the least. The friction of a tire on pavement generates heat, and too much heat degrades high-speed performance and can accelerate aging and failure. C is the lowest permissible rating. Temperature ratings correlate to speed, with C representing 85-100 mph, B representing 100-115 mph, and A covering speeds above 115 mph.
Notes: Arguably, the temperature rating -- like the "Z" speed rating -- is redundant, because it's tied to a speed rating that's presented with greater specificity in the service description. However, it's wise not to buy replacement tires with a rating lower than the originals', and it's a lot easier to match one of three temp ratings than it would be the 11 different speed ratings in the service description.
It's impossible to translate treadwear ratings to miles because where and how people drive plays a critical role. That said, if you think your tires wear out too quickly, consider a higher rating.
The same goes for traction, but understand that changes in one characteristic typically change others, be it treadwear, noise, ride quality or price.
Tire Age/Date of Manufacture
Unlike the other, more-prominent specs, the Department of Transportation's Tire Identification Number is of interest to tire owners and buyers alike -- mainly because it includes the week and year of the tire's manufacture, and thus its age. Tire age, not just wear, has become a safety concern.
Found close to the rim, the TIN consists of a series of 10-12 letters and numbers that -- like a vehicle identification number -- are of little use to a consumer. But the last four numbers represent the birth week and year of any tire built since 2000.
DOT h35R YC24 4305
The tire above was manufactured in the 43rd week of 2005. Tires built before 2000 used a three-digit code, where the year was reduced to a single digit. If the tire above were from 1997 rather than 2005, its code would be 437. Would 437 also be the code for a tire made in the 43rd week of 1987? Unfortunately, yes, it would -- and that's why four digits are now used.
Recently, the effect of tire age on safety has become a concern. Unfortunately, climates and how well a tire is cared for affect its aging, so there are no universal rules. Most tires wear out before age becomes an issue, but some automakers -- mainly German ones -- recommend replacement after six years in service, regardless of wear. Most automakers agree that 10 years is the maximum safe lifespan for any tire, including a spare that has never been used. When buying new tires, it's wise to check their birth date. Treat them like milk: Your family might finish a gallon before its expiration date, but then again, it might not. Why take the chance? For the same money, you should get the freshest milk -- or tires -- you can find. You might wear the tires out long before they're due for retirement, but why buy a set whose clock is already ticking?
What's Not on the Sidewall: The Proper Inflation Pressure
If you look closely enough, you'll probably find a maximum-pressure figure on a tire's sidewall.
Don't do it. This is not the recommended pressure for you to use; it's the maximum rating for the tire, irrespective of the vehicle on which it's used. Invariably, it's dramatically higher than the pressure you should be using.
New cars present the proper inflation pressures on the driver's doorjamb, as required by law. For more information, see Tire Maintenance.
(C) 2013, Cars.com; distributed by Tribune Media Services
If you have recently bought a vehicle, or you have been driving your car or truck for a while but haven’t thought to check out what kind of tires you have, you may be wondering how to figure out what your vehicle is fitted with.
There are many different kinds of tires, and each has been designed for a different driving purpose, and for differing conditions. One main differentiating factor in tire type is what weather conditions it has been designed for – winter, summer, or all seasons.
If you are unsure what kind of tires are on your vehicle, then read on, as we have some quick and easy ways to help you identify them different types of tires, which is especially important if you are planning on buying new ones.
Fairly easy to identify, winter tires always have a pictogram with a snowflake and mountains on their sidewall. This symbol - called 3PMSF for Three Peak Mountain Snowflake - means that the tire meets international standards for use in harsh winter conditions, making it a safe and reliable tire for anyone who drives in snowy, slippery, and extremely cold conditions. The tread depth of a winter tire is always at least 4 mm, to ensure a longer life in severe winter conditions.
If you are curious about the optimum outdoor temperature range for winter tires, generally, this value is related directly to the rubber compounds used in their manufacturing. If they bear the three-peaked mountain and snowflake logo, it means these winter tires have been tested in winter conditions under 40 degrees Fahrenheit.
While this might seem extreme, temperatures this cold do occur in parts of Canada from time to time. Regular winter tires marked with the M+S logo should be installed when the weather dips under 7 °C, or sooner if snow and ice start falling in your region.
If you are wondering if you have summer tires installed on your vehicle, there are a few features you can used to identify them. Summer tires are not quite as common as say, all-season tires, and tend to be found installed on high performance vehicles such as sports cars, or cars used solely during the summer months, such as vintage cars. Other features of summer tires include:
As you have read, summer tires are best suited for warm weather driving, but you may have questions about what the ideal summer tires temperature range might be.
The suggested temperature range for summer tires is when the weather hits above 45 °F or 7 degrees Celsius. In most parts of Canada, this means that summer tires are best installed near the end of the spring season, or at the beginning of summer – and are taken off and replaced with your all-season tires at the beginning of fall, still depending, of course, on where you live.
One of the most popular types of tires is the all-season tire. If you are wondering if those are the ones equipped on your vehicle, then here are a few features to look for:
Because they are called all season, these types of tires can be used all year round, as long as you are driving in average conditions.
However, if you want to know the temperature range for all-season tires, you should install them when the temperature is between 30 °F and around the freezing mark in Canada of 0 degrees Celsius. These tires will perform well during the winter months, but if you live in a region where you get a lot of snow and ice, or you travel on less well-kept roadways, then you may want to think of putting winter tires on your vehicle when the snowy season begins.
Of course, if you have any questions about what kind of tires to install on your vehicle, or need additional help determining what kind of tires you currently have on your car or truck, it’s best to reach out to a team of tire experts, like the people at blackcircles.ca. Our team is available to answer all your questions on tires, and we can also help find the perfect set of new tires at the best prices in Canada. Just reach out to us by email, phone or use our online chat, and we will be happy to help you out.
discover our best 2021 summer and all season tires
Irina Zverkova
Estimated reading time: 4 minutes
134243
RIA Novosti
Tires are one of the most important components of a vehicle to ensure driving safety. Proper use of summer and winter tires during the season improves handling and saves the car owner money. But some drivers not only postpone changing tires depending on the weather, but also continue to use the same tires for several seasons. At the same time, wheel wear becomes more and more, and the threat that the tires will not cope with holding the car increases.
The tire tread is responsible for connecting the car to the road.
This is the outer layer of rubber, which contains a certain pattern, suitable for different operating conditions. For summer tires, the removal of water from the contact patch is relevant, for winter tires - improved grip on slippery surfaces, for off-road tires - maximum cross-country ability. Regardless of the purpose of the tire, one of the important characteristics of the tread is its height or depth. This is the distance from the outer edge of the tire to the "bottom" of the groove. For new modern car tires, the height starts from 5 mm. For ordinary summer passenger tires, this value is 6–8 mm, for winter tires it is 8–10 mm, for SUVs it is 15–20 mm.
When the tread wears out (decrease in its depth), the driving properties first of all suffer: the car is more prone to aquaplaning. Winter tires lose some of their properties, which are provided by special sipes and studs. It is important to consider that different brands and models have different rubber composition, so some wheels “run” longer.
The driving style also affects wear - more aggressive starts and active braking shorten the life of the tire.
9 is considered critical for tire wear0022 tread height of 1.6 mm for summer tires and 4 mm for winter .
Height can be measured using the ruler with the depth gauge or vernier caliper.
Those who do not have such tools can use a regular 10-kopeck coin placed in one of the grooves. If the word "kopecks" is hidden, it means that the tire is almost new and does not require replacement. If the tread covers only the floral ornament on the winter tire, then it will soon need to be changed; if it’s in the summer, the replacement will have to wait. If only the rim of the coin is hidden, you need to urgently install new tires.
On the left is a worn tire, on the right is a nearly new tire. Photo: AiF / Irina Zverkova Many modern manufacturers make wear indicator on tires (this is a protrusion perpendicular to the axis of rotation of the tire) or lay a special colored layer that becomes visible when the tire is erased.
Their manifestation serves as a signal for the car owner to change tires.
It is important to monitor not only the tread depth, but also the wear uniformity . To be sure that the wheel is in good condition, it is better to measure the tread depth at different places around the circumference along the entire width of the tire. If the inner or outer part is worn out more, then the wear of the tread is taken into account at a minimum value, and it is better for the owner to check the wheel alignment / collapse of the car.
If the vehicle has frequently been driven on bumpy roads, climbed curbs, or the tires have been run half-flat, the sidewalls may have dents, holes, cuts or cracks . It is better to check their condition at the tire shop before the wheel is flat at the most inopportune moment. For example, it may not withstand the loads in a turn, burst and provoke an emergency. You should be especially careful about such damage on low-profile tires.
On average, tires last about 6 seasons , after which it is better to replace them. Improper storage and aggressive riding can shorten the lifespan. You also need to pay attention to the expiration date of the tire and the date of its production when buying, because polymers, unlike metal, can break down and lose their properties over time.
If it is not possible to update all four tires, then, as a last resort, you can put new rubber on the drive wheels. But needs to be changed exactly a pair of , otherwise the vehicle's handling may be severely impaired.
See also: When to change tires to summer tires →
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The right choice of car wheels will allow you to move in comfort and safety.
Rubber must strictly correspond to the season, road and temperature conditions. Incorrect use of wheels significantly increases the braking distance, the service life of the wheels, and the economy of movement. It is not surprising that manufacturers produce summer and winter tires, and today universal all-season tires are becoming especially popular. It is worth figuring out how to distinguish winter tires from summer tires, and for this you need to study the main characteristics of the wheels.
Tires for the cold season are characterized by a carved and deep tread pattern, which can look like a familiar herringbone or chaotic depressions. Lamellas or zigzag cuts on the tread are the virtues of winter tires. It is they, as well as checkers and deep grooves, that provide effective removal of snow and water, increase the coefficient of adhesion on the road. There are two main types of tread pattern for winter:
Scandinavian - the pattern is sparse, the checkers are staggered and look like rhombuses, there is a noticeable distance between the elements of the pattern;
European - the pattern is located diagonally, the network of channels is well developed, powerful lugs are located on the periphery of the tread, there are a large number of thin slots - lamellas on the surface.
Summer tires have shallow tread grooves designed to expel water, the number of sipes is kept to a minimum. There is no micro-pattern in the wheels for summer.
Spikes are another criterion of seasonality. There are no summer studded tires, and winter studding should be chosen carefully. The studs are designed for driving on ice, providing good grip where other wheels slip. They should not be located in two rows on the sides of the tires - this will not shorten the braking distance at all, and the spikes themselves will fly out after several trips. High-quality studding suggests an asymmetric or snake-like arrangement of spikes.
In addition, rubber for winter tires is softer and more elastic, it is visible to the naked eye for an experienced driver. This is easy to determine even by touch, since there is an order of magnitude more rubber in the rubber compound, which allows the tires not to freeze at low temperatures. Summer tires, on the contrary, are more elastic - there is less rubber in them, because in the heat soft tires “float” and do not hold the road.
For safety reasons, summer tires are resistant to wear and high temperatures.
During operation, winter tires warm up and therefore do not lose their elasticity and softness. On winter snowy or icy roads, this provides maximum grip, effectively shortening the braking distance. Summer tires cool down at speed, becoming more shaped and firm.
An important quality of rubber, which makes it possible to distinguish between summer and winter tires, is the maximum permissible speed. In winter, even on the highest quality roads, it is not recommended to drive faster than 140 km / h; summer tires are more democratic in this matter.
Despite everything, even a novice driver will be able to determine the seasonality of tires by special designations used by manufacturers. The letters M + S (mud and snow), as well as W (Winter - winter) guarantee comfortable driving in snow and mud, in some cases MS is the marking of all-season tires. Also, an image of the sun (for summer) and snowflakes (for winter wheels) is applied to the side surface of the wheels.
