Different Tyre Tread Patterns
Also called tyre tread designs, tyre tread patterns are the arrangement of continuous ribs, independent tread blocks, circumferential and lateral grooves, as well as the thin sipes molded into the tread to fine-tune noise, handling, traction and wear. Tyre treads patterns feature different basic designs to help them meet anticipated driving conditions.
A symmetric tread pattern (Multi Directional) is the most common and features continuous ribs or independent tread blocks across the entyre tread face where both inboard and outboard halves feature the same pattern. Tyres featuring symmetric tread patterns allow using multiple tyre rotation patterns.
An asymmetric pattern is designed to blend the requirements of dry grip and water dispersal/snow traction where the tread pattern changes across the face of the tyre. An asymmetric tread pattern usually incorporates larger tread ribs/blocks on the outboard side to increase cornering stability on dry roads by offering greater contact area. This also helps to reduce tread squirm and heat buildup on the outside shoulder. The inboard side usually features smaller independent tread blocks to aid wet and/or winter traction when driving straight ahead. Tyres featuring asymmetric tread patterns allow using multiple tyre rotation patterns.
A directional (also called a unidirectional) tread pattern is designed to roll in only one direction. It incorporates lateral grooves on both sides of the tyre’s centerline that point in the same direction and result in v-shaped tread blocks. These grooves enhance hydroplaning resistance at high speeds by pumping water more efficiently through the tread pattern. Unless they are dismounted and remounted on their wheels to accommodate use on the other side of the vehicle, directional tyres are to be used on one side of the vehicle and are intended to be rotated from the front axle to the rear axle. If different tyre sizes are used on the front vs. rear axle, the tyres become location-specific and prohibit tyre rotation unless remounted.
May be of any tread pattern but the tread blocks contain many small grooves called sipes, which help disperse water and provide additional grip on snow and ice. A different rubber compound is also used allowing the tyre to remain flexible at low temperatures. When combined with the advanced tread design this provides much higher levels of grip when the temperature is below 7oC and a safer drive.
Asymmetric and directional tread patterns have v-shaped tread grooves that are offset compared to the centerline of the tyre. Tyres featuring asymmetric and directional tread patterns must be treated as directional tyres for tyre rotation. However, if different tyre sizes are used on the front vs. rear axle, they become location-specific and prohibit any tyre rotation.