Tire Tread Patterns(Lea en español)
Also called tire tread designs, tire 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. Tire tread patterns feature different basic designs to help them meet anticipated driving conditions.
Symmetric Tread Patterns
A symmetric tread pattern is the most common and features continuous ribs or independent tread blocks across the entire tread face where both inboard and outboard halves feature the same pattern. Tires featuring symmetric tread patterns allow using multiple tire rotation patterns.
Asymmetric Tread 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 tire. 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. Tires featuring asymmetric tread patterns allow using multiple tire rotation patterns.
Directional (Unidirectional) Tread 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 tire'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 tires 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 tire sizes are used on the front vs. rear axle, the tires become location-specific and prohibit tire rotation unless remounted.
Asymmetric and Directional Tread Patterns
Asymmetric and directional tread patterns have v-shaped tread grooves that are offset compared to the centerline of the tire. Tires featuring asymmetric and directional tread patterns must be treated as directional tires for tire rotation. However, if different tire sizes are used on the front vs. rear axle, they become location-specific and prohibit any tire rotation possibilities.