The shape of the tyre tread pattern:
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Directional. Pattern with a characteristic V-shape. Among other things, such rubber is considered to be especially effective on wet surfaces — in rain, on snow, with an abundance of melt water, etc.: the pattern provides effective water drainage, reducing the risk of hydroplaning and increasing grip. Also, these tyres are well suited for high-speed sports cars (although, of course, their speed rating and specialization may be different). When installing directional tyres, the direction indicated by the manufacturer must be kept.
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Symmetric. The pattern without signs of directionality is the same both on the outer and on the inner part of the tread. These tyres are easier to manufacture than directional or asymmetric tyres, and are generally cheaper, while still having good performance on a flat and dry surface. In addition, symmetric tyres are as simple as possible to install, they do not need to follow the direction. However, for hard conditions, particularly wet weather, they are poorly suited. So, typically, such tyres are designed mainly for city cars used on short trips on relatively high-quality roads.
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Asymmetric. Tyres with a different pattern inside and outside the tread. Each of these parts plays a role: the inner part provides water evacuation and reduces the risk of aquaplaning, while the ou
...ter part provides the necessary rigidity for manoeuvrability and stability. While installing, you need to take into account the location of the outer and inner sides, they usually have the appropriate marking. Asymmetric tyres are considered the most advanced, although, of course, the actual characteristics and cost of such products may vary, depending on the brand and the general level. Such tyres are designed mainly for cars of medium and top levels; they are often supplied as factory equipment for advanced cars.Tyre wear resistance rate according to the Treadwear standard issued by the US National Highway Traffic Safety Administration.
This rate indicates how far the tyre is able to travel until the tread reaches a critical level of wear. Treadwear is indicated in conditional points; formally, every 100 points correspond to 48,000 km (30,000 miles). However, it should be noted that testing according to this standard is carried out under perfect conditions — on flat roads, without numerous sharp accelerations and brakings, at a stable temperature, etc. Therefore, real wear resistance, usually, is lower by at least 20 – 30 %; and for a full guarantee, the claimed indicator is generally recommended to be divided by two. For example, formally the value of Treadwear 240 corresponds to a mileage of 48 × 2.4=115.2K km — however, in fact it is hardly worth counting on more than 90K km, and it is best to keep on the value of 55 – 58K km.
Generally, Treadwear ratings up to 250 are considered fairly low, 251 – 300 are considered average, 301 – 350 are above average, and over 350 is typical for
the most durable tyre models. Note that this characteristic is given mainly for summer, less often — all-weather tyres; winter tyres should be quite soft, which makes it difficult to achieve more or less worthy wear resistance rating.
