Tire Speed Rating Chart
Tire speed rating or the speed index/symbol specify the top speed at which the tire can carry a load corresponding to its load index, under service conditions specified by the manufacturer.
The speed rating is identified as a part of the tire size designation or the tire’s service description, together with the load index.
The speed rating system as it is used today was developed in Europe as a response to the need for classifying tires into standardized speeds. It describes the top speed for which a tire is certified.
Speed rating on tires is expressed by a letter from A to Z (the speed symbol), ranging from 5 km/h (3 mph) to above 300 km/h (186 mph). For e.g. the letter "T" defines the maximum speed limit at 190 kph/118mph (Please see the tire speed rating chart below).
A tire rated with the letter "Z" in the tire size designation (i.e. P275/40ZR17 93W or 275/40ZR17 93Y) is the tire which have a maximum speed capability above 240 kph/149mph. Tires having a maximum speed capability above 300 km/h (186 mph) must have "Z" in the size designation and the service description must include Y in parenthesis (i.e. P275/40ZR17 (93Y)).
Tire speed ratings
|Speed Symbol||Speed (kmh)||Speed (mph)|
|(Y)||ZR**||Above 300||Above 186 (consult manufacturer)|
* Tire manufacturer may or may not (is not obligated to) include a "Z" in the size designation.
** Tire manufacturer must include a "Z" in the size designation.
Please note that the chart data should be verified with the tire/wheel manufacturer. This is for informative purposes only. The tyresizecalculator.com is not responsible for any errors that may arise with its usage.
See the Load index chart.
Check out other charts: Tire size chart, Tire conversion chart.