Considering that many manufacturers recommend using wider profile tires in summer and narrower ones in winter, the service book may indicate several sizes. We do not recommend installing tires of a different size, since car manufacturers have tested the car in various conditions and selected the optimal tire size that ensures the safest mode of operation of the car. Tires of the recommended sizes have a certain circumference by the outer diameter, so installing tires of a different size will distort the readings of the mileage counter and speedometer.
When choosing tires, you need to pay attention to the maximum permissible speed of the tire (see table 14.2). It is important that it is not less than the maximum speed of the car. In addition, the permissible load capacity of each tire (see table 14.1) must not be less than half the maximum mass per axle of the vehicle.
Depending on the conditions in which the tires will be used, their seasonality and tread pattern are selected.
In summer, during rain, when driving at high speed, the car may become uncontrollable, as the tire will slide (float) on the surface of the water. This effect is called aquaplaning. In order to avoid this, tires are provided with lamellas (grooves) of a special shape, which are able to effectively drain water from the contact patch of the wheel and the road. Very often, such tires are marked accordingly - "RAIN" (rain) or "AQUA" (water). It should be noted that if there is no such marking, this does not mean that these tires cannot be used in the rain.
In winter, snowy and icy sections of the road create a problem for drivers. The car becomes difficult to control on such sections, which can lead to an emergency situation. This problem is solved in the following way: winter tires have a rougher tread pattern and are often equipped with studs. Such tires are marked accordingly "M+S" ("Mud" + "Snow" - mud and snow) and/or "WINTER" (winter).
You should not use winter tires in the summer, as they become quite soft at elevated temperatures. Such tires are subject to rapid wear in the summer and do not provide safe operation of the car. Summer tires, on the contrary, become very hard in the winter and do not provide good traction.
Some manufacturers produce all-season tires that are suitable for use in both winter and summer conditions. However, they are generally inferior in performance to seasonal tires. They are more difficult to manufacture, so they are usually more expensive than seasonal tires.
Sometimes there is an inscription on the tires "ALL SEASON" (all seasons) or "ALL WEATHER" (any weather). When purchasing, you need to take into account that these tires may be produced for hot countries, where winter colds remain at around 0°C and, naturally, are not suitable for our winter.
Make sure that the tires you buy comply with international and Russian standards. Tires that have passed certification are marked with the letter "E" (which indicates compliance with European standards) or the inscription "DOT" (which indicates compliance with American standards), and sometimes bear both of these markings.
Regardless of international certification, all tires sold in Russia must have a certificate of conformity issued by the Russian State Standard, which conducts its own tests. The seller must present the certificate at the first request of the buyer.