The all-season passenger tire Yokohama RY818 is one of the models in the Delivery Star lineup, which translates to "delivery star". This is the most accurate term that defines the scope of application of this tire. This model was specifically designed for small-tonnage commercial vehicles - light trucks, vans, and minibuses, which are mainly operated in urban and suburban road conditions. In addition, the tire is favorably distinguished by a very wide range of sizes for its category, starting from 155 R12 and ending with 235/60R17. This feature allows the tire to be used on most modern models of commercial vehicles.
Tread pattern design
The design of the symmetrical non-directional tread pattern was obtained using computer modeling tools. The tread is built according to the classic canons of tire construction and contains four longitudinal ribs, two of which form the central part of the tread, and the other two are shoulder zones. This testifies, first of all, to the desire of Japanese specialists to apply those technical solutions that have the greatest efficiency at the lowest cost. Such a balanced approach allowed us to keep the cost of the final product at an acceptable level without harming the main working characteristics of the tire.
One of the characteristic features of this commercial tire is the massive size of the tread elements. This allows the Yokohama RY818 tire to cope with a large external load without any problems, as well as achieve optimal pressure distribution over the entire contact patch area, which ensures even tread wear and, therefore, the durability of the tire.
As mentioned earlier, the central part of the tread contains two wide longitudinal ribs. At the same time, each rib is a series of separate blocks of a rhombic shape. These blocks form numerous sharp edges, which provided the tire with good traction and coupling characteristics on various types of road surfaces. Also, it is impossible not to note the rounded corners of these tread blocks, thanks to which it was possible to significantly reduce the level of resonant noise.
The shoulder zones of the tread have not only very massive sizes but also a minimum profile radius. Due to this, it was possible to achieve a significant increase in the contact patch area, giving it a rectangular configuration at the same time. Such a contact patch is characterized by a more even distribution of pressure, which significantly reduces the likelihood of uneven tread wear and, therefore, increases the mileage.
Reliable behavior in rainy conditions
Even heavy commercial vehicles in rainy conditions are prone to aquaplaning. Therefore, the same safety requirements for driving in wet conditions are imposed on the Yokohama RY818 tires for commercial vehicles as on ordinary models. In this case, Japanese tire engineers equipped this model with three very wide and deep longitudinal drainage grooves. These elements of the drainage system, due to their large size, can accommodate a very large amount of water, which made it possible to significantly increase the tire's resistance to aquaplaning in the entire speed range. In addition, the tread blocks are equipped with very long straight lamellas. These lamellas are also designed to improve coupling in wet conditions. Their principle of operation is very similar to the functioning of car windshield wipers. Such a combination of drainage grooves and straight lamellas made it possible to ensure excellent coupling with a wet surface, making driving in these conditions safer.
Main features of the Yokohama RY818 tire
- A symmetrical non-directional tread pattern, the design of which was obtained using digital development tools, provides excellent coupling in any conditions;
- The reinforced construction of the tire sidewall reliably protects it from cuts and punctures;
- Four massive longitudinal ribs made it possible to significantly reduce rolling resistance, which significantly improved fuel efficiency;
- Excellent resistance to aquaplaning is provided by the effective combination of a high-performance drainage system and numerous straight lamellas working on the principle of car windshield wipers;
- Wide shoulder zones with a small radius profile made it possible to give the contact patch a large size, a rectangular shape, as well as ensure optimal pressure distribution and even tread wear;
- The composition of the rubber mixture is selected taking into account the specifics of the tire operation on commercial vehicles, which made it possible to additionally reduce rolling resistance and increase the durability of the tread.
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