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Motorcycle Tire Speed Ratings
Speed Ratings
Many of today's automobiles come equipped with speed rated Original Equipment
tires. Speed rating passenger tires originated in Europe, where highway speeds
can exceed 100 mph(160kph). The speed rating indicates the maximum speed a
properly inflated tire will withst& for a determined time. Testing for speed
rating certification is conducted in a laboratory setting.
NOTE: The speed rating is void if the tires are worn
out, damaged, repaired, retreaded, or otherwise altered from their original
condition. If tires are repaired, retreaded, or otherwise altered, they should
not be operated at higher than normal highway speeds.
| SPEED SYMBOL | SPEED MPH | SPEED KPH |
| M | 81 | 130 |
| N | 87 | 140 |
| P | 93 | 150 |
| Q | 99 | 160 |
| R | 106 | 170 |
| S | 112 | 180 |
| T | 118 | 190 |
| U | 124 | 200 |
| H | 130 | 210 |
| V*(VR) | 149 | 240 |
| W**(ZR) | 168 | 270 |
| Y**(ZR) | 186 | 300 |
*Current tire speed rating markings include the use of the service description to identify the tire's speed capability (P215/65R15 95V -maximum speed 149 mph).
**Any tire with a speed capability above 149 mph(240(kph) can, at the tire manufacturer's option, include a "ZR" in the size designation (P275/40ZR17). If a service description IS NOT included with the size description, the tire manufacturer must be consulted for the maximum speed capability(P275/40ZR17--speed capability is >149mph). If a service description IS included with the size description, the speed capability is limited by the speed symbol in the service description (P275/40ZR17 93W = maximum speed 168 mph(270kph).)
Speed Rating Characteristics
Tires have always had the ability to change an automobile's driving
characteristics. Technology has given the tire an important role as a component
of the automobile suspension. The speed rating of the tire is an indicator of
the tire's performance capability. Improving the tire's performance capability
will normally benefit an automobile's performance. Conversely, decreasing the
tire's speed rating generally lowers the tire's ability to contribute to the
automobile's performance. Changing from the O.E. tire speed rating to another
performance level tire will probably change handling in areas such as:
1. Steering Response 4. Cornering 2. Braking 5. Evasion/Recovery 3. Traction
