Directional tires are tires with tread patterns that are designed to rotate in one direction. The primary benefit of directional tires is the reduced chance of hydroplaning and increased traction on wet road surfaces.
Hydroplaning occurs when a layer of water gets underneath a tire causing it to lose contact with the road. Directional tires help reduce hydroplaning by utilizing a tread pattern consisting of v-shaped grooves that all point in the same direction. Because the tire is designed to rotate in only one direction, the grooves channel water more efficiently at high speeds compared to other tread patterns.
Due to their design, directional tires are rotated front-to-back and not side-to-side or in an x-pattern. To use directional tires on the other side of a vehicle, the tires need to be remounted. Remounting is also necessary to rotate the tires if the vehicle has front and rear tires of different sizes.
Directional tires can have the groove pattern on both sides of the centerline or combined with an asymmetrical tread pattern where the grooves are offset from the centerline. The asymmetrical design provides the water-channeling capability of directional treads with the dry surface traction of asymmetrical treads, and they are treated as directional tires for rotation purposes.
If directional tires are accidentally mounted backwards, the tires won’t suffer damage, but drivers should slow down in wet weather and get the tires mounted correctly as soon as possible.