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 "V" defines the maximum speed limit at 149mph/240 kph (Please see the tire speed rating chart below).
"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/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 Chart
Disclaimer:
Please note that the chart data should be verified with the tire/wheel manufacturer. This is for informative purposes only.
| Speed Symbol | Speed (mph) | Speed (km/h) |
|---|---|---|
| E | 43 | 70 |
| F | 50 | 80 |
| G | 56 | 90 |
| J | 62 | 100 |
| k | 68 | 110 |
| L | 75 | 120 |
| M | 81 | 130 |
| N | 87 | 140 |
| P | 94 | 150 |
| Q | 100 | 160 |
| R | 112 | 180 |
| S | 112 | 180 |
| T | 118 | 190 |
| U | 124 | 200 |
| H | 130 | 210 |
| V | 149 | 240 |
| W ZR* | 168 | 270 |
| Y ZR* | 186 | 300 |
| (Y) ZR** | Above 186 (consult manufacturer) | Above 300 |
* 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.
