Tire Speed Ratings
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.
“Z” Ratings
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/149 mph. 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 (ie. P275/40ZR17 (93Y)).
Tire Speed Ratings Chart
Please note that the chart data should be verified with the tire wheel manufacturer
This is for informative purposes only.
** Tire manufacturer must include a “Z” in the size designation