I remember ten years ago, I was walking along Nevsky and carrying two new tires. Before I got home, how many jealous eyes of car owners I experienced on myself! Today you don't have to sign up for wheels and stand in long queues. The assortment of tires is already so rich that the eyes run away. "Michelin", "Goodyear", "Viking", "Pirelli", "Nokia" - each of the huge, world-famous companies produces the widest range of tires of any size for all types of cars.
In order to purchase the exact tires we need, we cannot do without a minimum of information about the types and labels of these products.
Diagonal tires have not been used in the civilized world for a long time. In Europe, tubeless tires are mainly used. However, for the countries of Asia and Latin America, where the operating conditions are not better than ours, many companies continue to produce tires of the most common types with tubes.
All tires can be divided into four groups: 1) passenger cars for ordinary cars, 2) reinforced cars, 3) light trucks, 4) all-wheel drive cars.
In the designation of a passenger car tire for ordinary cars size 175/70R13 80S the first three digits indicate the conditional width of the tire profile (175 mm); two digits after the fraction - the index (or series) of low-profile, meaning the ratio of the height of the profile to its width in percentage (70%); letter R - radial; number 13 - wheel bore diameter in inches; last two digits - payload index (in this case the permissible load is 450 kg); letter S - permissible speed index (up to 180 km/h). If there is no fraction and no low-profile index, then the ratio of profile height to width is 80-82%.
The passenger car reinforced tires have the additional inscription "Reinforced", i.e. "reinforced". They are stiffer, designed for high internal pressure and used on wagons or vans (pickups) of low capacity on the basis of passenger cars. They can, therefore, be safely used on conventional vehicles with the same tire pressure.
The next group is light truck tires, which are even stronger, and after the size designation have an index C for commercial vehicles. In addition, these tires have a fractional payload index. The fact is that the load on each of the two rear wheels is slightly reduced when installing gable rear wheels. Therefore, the fractional index indicates the load on single and dual tires. These tires are designed for an internal pressure of 3.0 to 5.5 kg/cm2. They are too rigid and therefore unsuitable for passenger cars.
All-wheel drive off-road tires not only differ in their specific dimensions but also in their highly branched treads, which provide improved traction characteristics when driving on unpaved roads. Many of them have an M-f-S index (for snow and dirt). However, there are also special high-speed tires with a relatively smooth road pattern.
Each tire in these four groups may differ from the other by its own speed index, which is placed immediately after the payload index. The most common load capacity indexes for domestic vehicles are as follows. ZAZ-1102 for 155/70R13 tires has a load capacity of 72 to 75, which corresponds to a load capacity of 355 to 387 kg. All VAZ tires have indices from 76 to 82 and payload from 400 to 475 kg, while Moskvich-Vicha-2141 has indices from 82 to 84 and 475 to 500 kg, respectively. The 205/70R14 tire for Volga is marked with 93-95 (650-690 kg) indices.
Sometimes the same tires for different purposes have different payloads. For example, a 165/70R13 tire for VAZ-2108 can be marked as 76S and 79H, which in the first case means 400 kg and 180 km/h, and in the second case 436 kg and 210 km/h. Of course, the second tire is of higher quality and more expensive. Recall: the letter L indicates that the tire is designed for a maximum speed of 120 km/h, M-130, N-140, P-150, Q-160, R-170, S-180, T-190, H-210, V-240 and W-270 km/h.
In most cases, alphabetic indexes can be ignored, as imported passenger car tires are usually designed for speeds not lower than zero. This is quite enough for our roads and cars.
The payload interval of the tires under consideration is not too wide (from 250 to 1450 kg), but the standard sizes are much larger. For example, for VAZ-2108 or VAZ-2109 we recommend only three tire sizes close in capacity: 165/70R13 795, 155R13 785 and 165R13 825. However, those wishing to have a car with a non-serial appearance can "shoe" it with 14-inch light-alloy wheels and 165/65R14 size tires. Thus to worry, that readings of speedometer will change, it is not necessary, as on external diameter this tire is almost equal to 165/70R13.
Today there are also more low-profile tires. Vehicles are fitted with 60, 55, 50, 45, 40 and 35 series tires on 14, 15, 16, 17 and even 18-inch diameter wheels. Tires of this type, for example for Lada, can be 185/55R14 or 195/50R15. Let's say at once, these tires are produced only in a tubeless version, and they are intended for high-speed cars and very good roads. They are unlikely to provide any benefits in our operating environment.
A few words about the selection of tires. The machine with standard wheels can be fitted with any tires that are close in size and load capacity. But when installing any tires on non-standard wheels, it is necessary to consult with specialists to clarify the purpose of these tires, the required internal pressure and, most importantly, to find out whether they fit in the wheel niches so as not to hit anything.
Fierce competition forces manufacturers to create both universal and highly specialized tires. Therefore, next to the all-season can be seen, for example, special autumn tires designed for driving on wet roads. There are many different types of winter tires - from relatively smooth, universal use, to the most coarse, used with spikes (very suitable for our avtoindent.ru winter uncleaned roads). Not only that, for convenience of buyers, the firm "Michelin" began to divide the tires of series "Pilot" even on the level of comfort provided by them: comfortable, sports and intermediate type. By the way, tires of this company in St. Petersburg can be purchased in "Elasta" (former Leningrad Tyre Repair Plant).
Buying the most suitable for your car "shoes" is not an easy task, it will require careful study of advertising information.