Comparison KAMA 1260 425/85 R21 146J vs KAMA NF202 235/75 R17.5 132M

The type of vehicle for which the tyre is intended. Different types of transport differ in weight distribution, control and movement features. Therefore, it is impossible to violate the recommendations for the intended purpose, otherwise you may encounter various troubles - from deterioration in controllability to tyre damage due to off-design loads.

- Trucks and buses. Tyres for trucks of various classes - from light trucks to powerful truck tractors of the "long-range" class. Tyres for buses, trolleybuses and other passenger vehicles are also defined in this category.

— Agricultural and special equipment. Specialized tyres for agricultural, construction machinery and other similar vehicles. Agricultural models are mostly characterized by large sizes and a deep tread pattern - the latter is necessary for efficient work on loose soils and in mud. Tyres for special vehicles often also have advanced "off-road" capabilities, which allows you to effectively move both on hard surfaces and on dirt roads or in mud at construction sites. The speed index for such tyres is usually low - such equipment does not need to be driven fast. There are exceptions to these rules, but they are rare.

The type determines the installation location for which the tire is designed. Different installation locations require different characteristics, which are taken into account in the design accordingly. It is impossible to violate the type compliance - this leads to undesigned loads, which increase tire wear and can even lead to such a dangerous incident as a tire “explosion”.

— Steering. Tires designed for installation on the steering axle of a truck. In this place, the wheels and tires are subject to additional torsional loads along the vertical axis (when the steering wheel is turned from side to side), which places increased demands on reliability.

- Presenter. Tires designed for installation on the drive axles of a truck, for which good grip on the road surface and high resistance to torsional loads along the main axis of rotation are extremely important.

— Trailed. This category includes tires intended exclusively for installation on trailers (as well as on other axles other than steering or drive axles) and not suitable for any other use. With this setup, torsional loads are relatively low, but the tire is often subject to heavy weight loads (for example, in tractor-trailers, most of the weight is carried by the trailer).

- Universal. Tires that allow any of the installation options de...scribed above. This option is convenient because by purchasing a set of tires of one model, you can provide them to all the wheels of the truck at once, without purchasing other tires. On the other hand, at the same cost, universal tires are often inferior to specialized tires in terms of performance characteristics.

— Steering / trailed. Tires best suited for use as either steering or trailing tires. See above for more details on each of these options.

Tyre profile width in millimetres. This designation is noticeably less common than inches (see Width above), but it is also used quite widely.

As for the width in the frame, in this case it is indicated by the distance between the sidewalls of the tyre installed on the disk and inflated (but not loaded). This is one of the parameters that determine compatibility with a particular disc: the tyre must be slightly wider than the rim. For the selection of rubber for specific disks in width, there are special tables.

On the modern market, among the popular sizes, there are such options in width: 205 mm, 215 mm, 225 mm, 235 mm, 245 mm, 265 mm, 275 mm, 285 mm, 295 mm, 305 mm, 315 mm, 385 mm, 425 mm, 435 mm, 445 mm.

Tyre profile height. This indicator determines how much the tyre protrudes above the disk. Specifies the profile height as a percentage of the width (see above). The lower the profile, the better the stability of the car on the road and the faster the rubber wears out; in turn, higher profiles are well suited for rough roads, primers and off-road.

In truck tyres, there are such options for profile height: 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%.

Tyre inner diameter in inches. This parameter determines the possibility of installing the product on a specific car, more precisely, on a rim: the bore diameter must correspond to the diameter of the rim. The dimensions of the disk can be clarified by its marking or according to the documents for the car, in extreme cases, measure it yourself.

For trucks, 17" or less is considered small, over 24" is considered large. The most popular sizes in between include 17.5", 19.5", 20", 22.5" and 24".

The load index characterizes the maximum weight under which the tyre can be safely operated. As in the case of the speed rating described above, this indicator cannot be exceeded, otherwise unpleasant consequences are possible, up to accidents. Also note that when selecting according to the load index, it is worth considering the distribution of weight along different axes of the vehicle. And it is worth considering the maximum possible weight when the truck is loaded, in accordance with what to select truck tyres for heavy loads.

The speed rating describes the maximum speed at which a given tyre can be safely driven. It is worth choosing a model according to this parameter in such a way that during operation it is not allowed to exceed the speed rating — this creates increased loads on the tyre and can lead to its damage (up to an “explosion”). And it is best to choose an option with a margin of at least 10 – 15 km/h — this will give an additional guarantee in case of emergency situations. For truck tyres, speed indices in the range of 100 – 130 km/h are considered popular, and these are the J speed rating(100 km/h), the K speed rating(110 km/h), the L speed rating(120 km/h) and the speed rating M(130 km/h). For agricultural machinery, the speed is much lower: index A6(30 km/h), index A8(40 km/h), index B(50 km/h), index D(65 km/h), index F(80 km/h) ). There are also high-speed truck tyres and less popular speed indices C(60 km/h), E (70 km/h) and G (90 km/h).

The rolling resistance index to which the tire corresponds. The higher this indicator, the lower the resistance, the less fuel is spent on overcoming it and the more economical the tire is. Efficiency indices are designated by letters of the Latin alphabet in order of decreasing efficiency: from A to G (lowest efficiency).

All other things being equal, more economical tires ( A, B, C, D) tend to cost more, but this difference is offset by fuel economy.

An index that determines the overall performance of a tire on wet asphalt. Identified by letters from A(highest) to G (lowest).

The higher this indicator, the stronger the tire “clings” to the wet road, the more efficient and safer it will be in bad weather, all other things being equal. It is worth noting that a low clutch index (E, F, G) does not mean that it is unsuitable for driving in rain or snow - you just need to be more careful on such tires. Conversely, a high index (A, B, C, D) does not relieve the driver of the need to be careful in difficult weather conditions.