The speed rating or speed index is represented by a letter and associated with the tyre’s maximum speed capability when operating at its maximum load carrying capacity. A tyre marked with a ‘Y’ speed rating, indicates it can be safely operated at a maximum speed of 300kph.
|Speed Category Symbol||Speed (km/h)||Speed Category Symbol||Speed (km/h)||Speed Category Symbol||Speed (km/h)|
*Consult tyre manufacturer for Speed and Load Capacity
When the letters “ZR” are included in the tyre size and followed by a service description, the tyre speed category is that included by the service description.
|Service Description Examples:|
|Tyre Description||Maximum Speed Capacity|
|225/55R 17 97W||270kph|
|225/55ZR 17 97W||270kph|
|255/40R 17 94W||270kph|
|255/40ZR 17 (94)*||Over 240kph*|
*Only tyres V, W or Y are included in this category.
The tyre manufacturer must be consulted to ascertain the tyre’s maximum speed capability when the tyre has a “ZR” symbol and no service description. The “ZR” symbol must appear in the tyre size designation for tyres having a maximum speed capability of over 300kph.