What do the numbers on the tires of the car mean?

Experienced car enthusiasts know that tires go a long way toward determining how a car behaves on the road. Therefore, they must comply with the vehicle and its operating conditions. The marking on them helps to choose the right tires - every driver must know what the numbers on the tires of the car mean.

What are they?

All used tires are divided into several classes:

  1. Summer. They operate on asphalt roads at positive temperatures and provide the best grip on dry surfaces in such conditions. They allow you to maintain a high driving speed and are not intended for use in the winter.
  2. Winter. They are used on icy road surfaces and at low temperatures. Thanks to the selection of materials and tread pattern, they provide good traction.
  3. All-season. A compromise between the first two types of tires. In the absence of significant temperature changes, they can be successfully operated all year round.
  4. Special. First of all, these include off-road and dirt-road off-road tires. The characteristics are closest to all-season tires.

Each of the mentioned types includes many models designed for different vehicles and operating conditions. And the markings on the tires help to understand this variety.

What the numbers say

There are different marking systems, European and American, the latter being of two types. Tires of European manufacturers are widespread in our country, therefore, the marking adopted by them will be considered below.

The most understandable is the designation of the manufacturer, for example Michelin, Pirelli, Bridgestone or others. No explanations are required here, each driver decides for himself what to choose, depending on financial capabilities. The cost of tires from leading manufacturers is higher than from little-known ones.

For a better understanding, let's analyze a typical marking, for example 195/70 R15 89H.

  1. First, the tire size is indicated, in our example it will be 195/70. The 1st digit indicates the width of the tire in mm, the 2nd is the ratio between the height of the tire and its width, expressed as a percentage. What in these numbers refers to what will help to make out the drawing.

    In fact, this ratio means that with the same width, the tire with the larger value will be taller. By the way, it allows in some way to compare different tire models. If you decide to put wide tires on the road for greater stability of your car (instead of 195/70, choose 205/70), then you need to take into account that the new ones will be higher, respectively, and the car will rise above the road, but this may already be unsafe. In some cases, it happens that the second digit is missing, that is, the marking looks like 195 / R15. This is the designation for a full-profile tire when the height-to-width ratio is 80%. Practice has established that in the conditions of our roads, the use of tires with a profile height of less than 50 is quite dangerous.

  2. Index R - design, means that the tire is radial.
  3. Index 15 - diameter (in inches) of the disc for installation, that is, this is how the inner diameter of the tire is indicated.
  4. An indicator of the permissible load, for example 89. This means that the permissible wheel load should not exceed 580 kg. The specific value is determined in accordance with the given table according to the index indicated on the bus.

    It is worth noting that it is a mistake to determine the total permissible load by multiplying the obtained figures by 4. It means the maximum load, and the operation of any device in the limit mode is an extreme case. Therefore, first of all, it is necessary, at least, to reduce the value of the permissible load by 20%. Well, it is necessary to take into account that the car may have different permissible axle loads - this is usually indicated in the operating instructions.

  5. Speed ​​index, in example H. Indicates the speed at which the tire can be driven. The specific allowable value is determined using reference data, in our example - 210 km / h.

Additional data on the tire

In addition to the information already given, the tire may contain other information, among which it is worth noting:

  1. Indication of the direction of rotation. This means that when installing a wheel with such a tire, this requirement must be observed.

  2. Symbol M S (mud plus snow). Instead, M