On the side of any tire you can see a lot of different symbols - numbers, letters, badges, etc. Knowing how to decipher these symbols, you will get the most comprehensive information about the bus.
All possible designations:
1. The most important parameter. This indicates the tire size. The first digit in the index indicates the width of the tire in millimeters, the second - the height of the profile as a percentage of the width. This is followed by a letter indicating the tire design and a number indicating the tire diameter in inches.
For example, the designation 195/65 R15 stands for: tire width is 195 mm, profile height is 126.75 mm (65% of the width), R is a radial tire (there are diagonal tires, but they are practically not found today), the landing diameter for Installation to disk - 15 inches.
Sometimes in a similar index there is no indication of the height of the profile (for example, 195 R15). This means that its value exceeds 80%. These tires are called full-profile. Often they are equipped with light commercial trucks and vans.
2. Index or load factor. Denoted by numbers from 0 to 130, but the most common range is from 71 to 110. Moreover, each combination has its own permissible tire load in kilograms.
Sometimes manufacturers point their tire capacity directly on the tire (in particular, this is mandatory for tires approved for sale in the USA). In this case, on the sidewall you can see the inscription Max Load and the load value in kilograms and British pounds. For example, Max Load 515kg (1135lbs).
Index Load kg
3. Speed index. It is denoted by Latin letters (see the decoding in the table) and indicates the movement with which maximum speed the tire is calculated.
Speed index / Speed, km / h / Speed, mph
B / 50/31
C / 60/37
D / 65/40
E / 70/43
F / 80/50
G / 90/56
J / 100/62
K / 110/68
L / 120/75
M / 130/81
N / 140/87
P / 150/93
Q / 160/100
R / 170/106
S / 180/113
T / 190/118
H / 210/130
V / 240/150
W / 270/168
Y / 300/186
ZR / 240+ / 149+
4. Such an inscription indicates a reinforced tire carcass, what is important for commercial vehicle tires. Therefore, instead of the word Reinforced on the side, often the manufacturer simply adds the letter C (which means commercial) to the designation of tire parameters. For example, 195/65 R15 C.
5. Country of manufacture of the tire. For example, made in France - made in France, made in Germany - made in Germany.
6. Tires with an asymmetric tread pattern on The sidewall is marked with the outer side of the body. It is labeled with the words Outwards, Out, Side facing outwards, etc.
7. Indication of tire fit to different operating conditions:
M + S - Mud + Snow: mud plus snow
As - All Season: All Season
Aw - Any Weather: Any weather.
Aquatred, Aquacontact, or an umbrella-shaped icon — special rain tires.
Snowflake pictogram - tires for harsh winter conditions.
If there is no similar designation on the sidewall, it means that the tire can only be used in summer, in warm weather.
8. tire performance - chamber or tubeless. It is denoted Tube Type (TT) or Tubeless (TL), respectively.
9. Sign of certification. On tires approved in Europe under Regulation No. 30 of the UNECE, it is a letter E inscribed in a circle and a digital index corresponding to the country that issued the approval. For example, Russia is assigned No. 22 in this list. The following is a long set of numbers - the number of the certificate of compliance.
Tires complying with the American standards additionally bear the DOT designation, in which data is not only encrypted on the test protocol number, but also on the tire manufacturer. For example, DOT MKR4 AJOR
10. Name or logo of the companytire manufacturer. For example, Michelin, Good Year, Yokohama.
11. Tire model. For example, Energy, SP Sport 9000, Turanza ER300.
In addition, on many tires you can find additional symbols:
Date of issue of the tire. This is a four-digit figure like 1109, which means the 11th week of production in 2009.
Regrooveable - tire with the possibility of additional deepening of the tread.
TWI (Tread Wear Indication - wear indicator track) - such a sign on the tire sidewall indicates the placement of a wear indicator on the tread (recall that in Russia its depth must be at least 1.6 mm). Usually this symbol is applied around the circumference in six places. It can be done in different ways. For many manufacturers, the indicator is a simple protrusion in the groove of the tread. When they are compared in height - the tire should go for recycling. In more advanced models, the indicator looks like a set of numbers indicating the residual tread height. As it is worn, the numbers are gradually erased.
Maximum Pressure - maximum cold tire pressure. Usually indicated in pounds per square inch (1PSI = 0.0069 MPa) or units of bar, almost equal to the atmosphere.
The arrow, sometimes with the inscription Rotation, indicates the desired direction of rotation of the tire with a directional tread pattern.
Tread Wear Index - Wear resistance index. Conventional value indicating how durable the tire is. For example, a tire with the designation 200 should theoretically have two times more resource than the analogue with the index 100. But in practice this can be achieved only in ideal conditions of the landfill or laboratory, where there are no factors such as driving style, quality of roads and t .d
Traction Index - tire grip index (A - Excellent, B - Medium, C - Satisfactory). It is determined in the process of testing at a special test site by a special method. It mainly assesses the quality of braking, rather than cornering stability.
Temperature Index - temperature index (A - excellent, B - Medium, C - Satisfactory). This indicator determines the resistance of the tire to high temperatures. The higher the score, the less the tire changes its properties when heated. Tests are conducted in the laboratory on a special stand.
Colored dots (white, red, yellow) on the sidewall indicate the easiest place of the tire relative to its center of rotation. This is where the valve should be installed. If on the tire there are both yellow (white) and red marks at the same time, then the latter is located in the hardest part of the tire.
Also, the tire sometimes contains designations indicating its special properties. In particular, RunFlat tires (RSC - RunFlat System Component) allow you to move for a while on the punctured wheel. In addition, there are models that protect the rim of the disc. As a rule, such tires are used by automakers of premium-segment cars.