Symmetric Tread Pattern
A symmetric tread pattern has continuous ribs across the entire tread surface. Both inboard and outboard halves have the same pattern.
Asymmetric Tread Pattern
Tyres that have asymmetric tread pattern are those which have different inboard and outboard tread pattern.
Asymmetric tyres are constructed to fulfill conflicting requirements, having good grip and water dispersal on wet and dry roads. The outboard pattern usually has larger tread ribs and bigger blocks to allow for stable cornering, while the inboard is designed for better water dispersal. Smaller inner blocks and higher density of canals improve the dispersion of water and heat.
Some tyres are asymmetrical and directional. Such tyres have markings on the side wall that
- show the correct turning direction, and
- show which is the inner and which is the outer side.
Unlike directional tyres, asymmetrical tyres may be mounted on any position on the car. It is very important that, when mounting, the side that reads outside is on the outside facing outward. As with directional tyres, faulty installation reduces its performance. If asymmetrical tyre is mounted wrongly, it can only be used as a spare tyre.
Directional Tread Pattern
Directional tyres are constructed to perform only when they are mounted to turn in the right direction. The direction of rotation is marked by an arrow on the sidewall of the tyre, and a mark direction or rotation. The tread pattern of these tyresalso indicates tyre’s proper turning direction.