Directional tyres must be mounted on the vehicle so that when the vehicle is moving forward, the tyres rotate in the direction indicated by the arrows on the side of the tyres. The wheels must not be switched from left to right when changing tyres, as this would reverse the direction of rotation!
A directional tire is actually a special form of a so-called symmetrical tire, where the direction of rotation does not matter. However, the design of a directional tire assumes that the specified direction of rotation is maintained during mounting. Since designers do not have to worry about the tire performing equally well in the opposite direction of rotation, they can optimize the tire design for only one direction of rotation. For this reason, a directional tire can perform better and is particularly suited for sports cars. A directional tread pattern drains water and winter slush better and, above all, faster, thus providing better traction. Overall, a directional tire better resists aquaplaning.
Advantages of directional tires:
- stability at high speeds
- very good wet performance
- low noise level due to the arrow-shaped design of the tread blocks
- attractive appearance
Disadvantages of directional tires:
- defined direction of rotation makes them difficult to use
How do I know a directional tire?
Fitting a directional tire:
As mentioned earlier, care must be taken when mounting a directional tire to maintain the direction of rotation. You cannot arbitrarily change the wheels from right to left without removing the tire from the rim and rotating it.
In exceptional emergency cases, the directional tire may be used in reverse for a short period of time. However, it is important to remember that a reversed tire does not have the same adhesion characteristics and to rotate or replace it at the earliest opportunity!
As long as the tire matches the dimensions listed in the vehicle documents, the directional tire can also be used as a spare wheel (to get to the workshop). However, a directional tire is not very suitable for this purpose, as it is directional and the tread may be in the opposite direction to the one needed.