Load index
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.
Speed rating
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).
Ply rating (PR)
Symbol for evaluating the bearing capacity of a tyre carcass. The ply rate indicator does not reflect the actual number of carcass plies in the tyre structure, but indicates the conditional compliance with the bearing capacity in comparison with the reference tyre based on cotton cord. In foreign-made rubber, the ply index is indicated by two numbers and the letters PR (Ply Rating) after them. Models released in the post-Soviet space are labeled similarly, but with a different index - HC (Bearing Capacity). The ply rating in truck tyres shows what maximum load limit the carcass of the rubber product corresponds to. The higher the value of the ply rate, the thicker and stronger the tyre, the greater its load capacity.
Tyre type
- Chamber (TT). In such tyres, it is supposed to use a separate inner chamber as an air reservoir, which is filled with air under pressure. Tube tyres were common earlier, they are now being phased out in favor of tubeless tyres. The main advantage of such models is that a punched pneumatic chamber can be sealed and used further. However, tube tyres add mass to the wheel, and friction between the tube and the tyre causes heat and accelerated tyre wear. In addition, in the event of punctures, chamber models almost instantly lose pressure, which promises a loss of control over the car. Tyres for the pneumatic chamber are usually designated with the TT (Tube Type) marking.
- Tubeless (TL). In tubeless tyres, air is held directly in the space between the wheel rim and the tyre. The sealing cavity is formed by a layer of rubber on the inner ring of the tyre, which has an increased gas tightness. Tubeless models are lighter than their chamber counterparts, which has a positive effect on vehicle handling and reduces fuel consumption. Also, tubeless tyres provide less chance of depressurization in case of punctures - the pressure in them is often systematically and gradually reduced, reducing the risk of loss of control over the machine. Tubeless tyres are marked with the designation TL (TubeLess).
Wet grip
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.
Noise level
The average noise level generated by a tyre while driving. The lower this indicator, the more comfortable this model will be, the less additional noise it will create.
