Directional tyres must be mounted on the vehicle in such a way that when the tyres are moving forward, they rotate in the direction indicated by the arrows on the side of the tyres. The wheels must therefore not be swapped from left to right when changing tyres, as this would reverse the direction of rotation!
A directional tyre is actually a special form of a so-called symmetrical tyre. However, the design of a directional tyre assumes that the specified direction of rotation is maintained during mounting. Therefore, designers do not have to worry about the tyre performing equally well in both directions of rotation, they can optimise the tyre design for only one direction. For this reason, a directional tyre 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 tyre better resists aquaplaning.
Advantages of directional tyres:
- 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 tyres:
- defined direction of rotation complicates their use
How do I know a directional tyre?
Fitting a directional tyre:
As mentioned earlier, care must be taken when mounting a directional tyre to maintain the direction of rotation. You cannot arbitrarily change the wheels from right to left without removing the tyre from the rim and rotating it.
In exceptional emergency cases, the directional tyre may be used in reverse for a short period of time. However, it is important to remember that a reversed tyre does not have the same adhesion characteristics and to rotate or replace it at the earliest opportunity!
As long as the tyre matches the dimensions listed in the vehicle documents, the directional tyre can also be used as a spare wheel (to get to the workshop). However, a directional tyre is not very suitable for this purpose, as it is directional and the tread may be in the opposite direction to the one needed.