What do the numbers and letters on the tires say?
What do the numbers and letters on the tires say?
The tire IDs represent their core features and are described using a tire ID or alphabet-dimensional tire ID that is typically carved on the lateral wall of the tire.
This tire ID indicates the dimensions of the tire and some of the important limitations for using tires such as tolerable load and maximum speed. In some cases, the internal or exterior wall of the tire includes information that is not inserted on the other side of the tire. The new car tires often have a rating in terms of adhesion, tire wear and temperature resistance. However, some pickups and chassis cars use the numeric pickup system or the top of the light pickups.
National Technical Standards
The DVTA tire ID is a sequence of the textual characters carved on the lateral wall of the tire and enables the detection of the tire and life specifications. This ID has been communicated by the US Transportation Office, but is used worldwide.
The DVI can be used to identify tires that are subject to product calls or are also used to know the end of the tire life. The recommended method of the British Tire Manufacturers Association (BRMA) issued in June points out that “BRMA members are seriously recommended. They do not have tires that have not been used. If they are more than 5 years old, they should not be employed and all tires must be replaced ten years after production.
The European Tire and Ring Technical Organization (ETRTO) and the Tire and Rings Association (TRA) are two organizations that apply national tire standards.
The purpose of ETRTO is to set up tire and ring standards in Europe. Tire and Ring Society, formerly known as the American Tire and Ring Association, is an American business organization whose task is to align technical standards. It is the agencies that are responsible for the implementation of the federal safety standards of motor vehicles (FMVSS). Canada also published rules for tires, including the Motor Vehicles Tire Safety Regulations (SOR 95-148).
All tire IDs that have been sale after July for road use in Europe must have an E badge. This tire ID can be written as uppercase (E) or lowercase letters (E). After this tire ID, a numerical is placed in a circle or a square and then another figure is inserted. The letter E (upper case letters) indicates that the tire has received the ECE Certificate of Certificate for Dimensions, Performance and Marking. The EEC has its dimensions, performance, and marking. The number inside the circle or square represents the country’s ID whose government has issued a tire confirmation. The last number outside the circle or square is the tire verification certificate number for which the type and size of the tire is issued.
Explanation about tire ID
The tire ID of the ISO metric ID contains a chain of letters and numbers as follows: a letter (or letters) selected to show the vehicle class for which the tire is used:
P: Car (Passenger Car)
LT: Style pickup (light truck)
ST: Special trailer (Special Trailer)
T: Temporary (exclusive application for “space keeper”)
The letter P in the tire ID indicates that the tire engineering is designed according to the TRA standards, and the lack of this is that the tire is designed and built based on ETRTO standards.
In practice, the standards of these two organizations are formed together and are relatively exchangeable, but given that the load bearing index in these two standards varies for a specific tire size, this exchangeability cannot be quite possible.
Number 2: “Nominal Width of the Cross” in the tire ID per millimeter unit; The wider point of both outer margins (wall to wall). The tire surface that is in contact with the road is usually less width.
Crooked characters for separation of characters.
Number 1 or 2 -digit: The dimensional ratio of the lateral wall height in a percentage of the nominal width of the tire cross -section. If this information is deleted, the assumed value is 1 % (if written, it should be xxx/1).
If the number is larger than 1, it will indicate the overall diameter of the tire per mm.
The selected letter to show the tire speed grading. This may be inserted at the end of the chain and after the load index. If the letter is Z, indicates a maximum speed of more than 1 km / h (1 mph), and the letters W or Y may be written after the load index.
A selected letter to show the structure of the tire trunk
B: Bias Belt (Bias Belt) (for tires that have drought rides for the car)
D: Qatari
R: Radial
In the absence of this character in the tire ID, the tire texture structure is the type of crusher layers.Number 1 or 2 digits in the Qatar Tire ID for which the tires are designed in inches. There is a rare exception to tires with metric diameter, in which the figure can be for example. In this case, the marker is 2 mm in diameter.Today a few tires are made of this size. In cases where the tire size has a decimal, this number can be longer; For example, many heavy transport trucks today use tires of 1.5 inches.
Number 1 or 2 digits: Load Index (Load Index); Some tires of pickups and light trucks have been approved for “dual use”. This means that these tires can be used in pairs. In this case, the two load indicators will be determined separately for single or pair use. For example, in the opposite image indicating the tire ID suitable for light pickups and trucks, the index is for single use, and the index is for use in pairs.Tires that do not have this index in this way lack the safety needed to use in the placenta.
Tire ID chart, specific features for light vans and trucks
Some light trucks and vans follow light truck numerical identification or light truck floatation systems. In these systems, instead of inserting letters at the beginning of the chain, the letters LT are used at the end of the chain of identifiers:
The tire diameter is listed in the above flotation system, but not in tires with a numerical identification system. 2-digit number: tire diameter in inches in the tire ID
x: character separator
3 or 4-digit number: in the tire ID, the cross-section width (cross-sectional area) of the tire in inches. If the tire diameter is not included, the section width that ends with a number 0 (for example, 7.00 or 10.50) indicates the aspect ratio of 92%, and if the section width does not end with a zero (for example, 7.05 or 10.55), which means that the aspect ratio is 82%. Today, these aspect ratios are often different in the products of different manufacturers.
The structure of the top of the car tire in the tire ID
B: Inclined belt
D: Qatari
R: Radial
2-digit number: in the text of the tire ID, the diameter of the wheel for which the tires are designed in inches. LT: specifies that the tire in question is designed for light vans and trucks. Inserting the load index and speed rating is not required in some cases for floating sizes. , but for tires approved for street and highway use, these identifiers must be included.
2 or 3 digit number: load index
1 or 2 character combinations of numbers or letters: speed rating
Additional signs
For example, if a tire size has two sets of numbers (12-6, 15-5.00, 24-11.2), the first number (15-5.00) indicates the approximate width in inches. and the second number (15-5.00) indicates the appropriate rim diameter in inches.
If the tire size consists of three groups of numbers (15×6.00-6, 12×12.00-26, 15×15.50-31), the first number (26×12.00- 12) indicates the approximate height in inches, the second number (12-26 x 12.00) indicates the approximate width in inches and the third number (12-26 x 12.00) indicates the appropriate rim diameter in inches.
Load index
The load index in a passenger car tire consists of a numerical identifier that specifies the maximum load (mass or weight) that each tire can carry. They measure wind at 36 psi (250 kPa), while P-Metric standards measure load capacity at 35 psi (240 kPa) wind pressure. These two standards are slightly different in terms of the capacity required for different wind pressures. All tires under the ETRTO standard that have the same load index will also have the same maximum permissible load, but tires with the P-Metric standard that have the same load index , they may have different load capacity depending on the size of the tire.
When comparing the load capacity of P-Metric tires in the TRA air pressure tables, decisions should always be made in consultation; Considering the load index alone is not enough to identify the right tire. For example: a standard load P205/50R15 tire has a load index of 84 and a load rating of 505 kg (1,113 lb) at an air pressure of 35 psi ( 240 kilopascals). A P215/50R13 tire with the same load index of 84 has a load rating of only 495 kg (1,091 lb) at 35 psi (240 kPa). Determined and installed according to their speed rating ID and based on the maximum speed of that vehicle (except for spare tires for temporary use).
In some parts of the European Union, it is illegal to use tires that are not suitable for the maximum speed of a car or motorcycle. The only exception is M+S tires, which, if used, must have a warning label containing the maximum speed allowed inside. car and be installed in the full view of the driver. Some manufacturers, if the buyer has ordered tires with a rating lower than the maximum speed of the car, install a speed governor device on the car. In some European Union countries, such as Germany, The use of tires with a lower speed rating is allowed under the condition that the car manufacturer has specified tires with a very high speed rating in the registration documents and the car cannot achieve this speed due to insufficient power.