Originally Posted by Symmetric, Asymmetric, Directional, Unidirectional - What Does This Mean?

When shopping for tires, it pays to make sure you're getting the right tread design for your driving needs. The three most common tread designs are: symmetrical, asymmetrical and directional/unidirectional. Each tread design serves a specific purpose that will effect driving characteristics and tire rotations.

Symmetric Tread Pattern

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. Two of our highest rated all-season tires with a symmetrical tread pattern are the Michelin Primacy MXV4 and Hankook Optimo H727.

Asymmetric Tread Pattern

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 typically incorporates larger tread ribs/blocks on the outboard side to increase cornering stability on dry surfaces by offering greater contact area. This also helps to reduce tread squirm and heat buildup on the outside shoulder. The inboard side usually has smaller independent tread blocks to aid wet and/or winter traction when driving straight ahead. Tires with asymmetric tread patterns allow using multiple tire rotation patterns. Two of our highest rated all-season asymmetrical tires are the Bridgestone Turanza Serenity Plus and Continental ExtremeContact DWS.

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Originally Posted by Are my Asymmetric Tires Running Backwards?

It's very common for a customer to get very excited over the tread pattern of their newly purchased asymmetric tires. While I agree the look of the grooves would lead you to have them pointing in a downward direction during rotation, the reality is there isn't a significant enough of difference for it to matter.

With an asymmetric design you need the larger shoulder block on the outside to take the abuse during cornering, this is more important than the direction of the groove on the inboard shoulder for water evacuation. The groove channels are small enough that the water will escape to the circumferential grooves when under speed. There's an unbelievable amount of force being exerted on the tire when the leading edge hits the road. Water is going to move through those lateral grooves out to the circumferential grooves for evacuation due to the force being exerted. Those grooves must also have an angle to them. While they would work just as well if they were perpendicular to the larger circumferential grooves, the tire would be very loud. By introducing an angle, noise levels are lowered.



Testing data and feedback on the tire is based on them mounted with the outside marking facing outside. The tire will perform as intended when installed in this manner. There's no left side and right design available. The fact remains, the engineers designing these tires are achieving the performance goals with this design. You'll see this on tires from all brands using an asymmetric approach.