 
                                         
                                         
                                         
                                        | Symbol | Max Speed (mph & km/h) | Symbol | Max Speed (mph & km/h) | 
|---|---|---|---|
| Q | 99 mph | R | 106 mph | 
| S | 112 mph | T | 118mph | 
| U | 124 mph | H | 130 mph | 
| V | 149 mph | W | 168 mph | 
| Y | 186 mph | 
| Symbol | Max Speed (mph & km/h) | 
|---|---|
| Q | 99 mph | 
| S | 112 mph | 
| U | 124 mph | 
| V | 149 mph | 
| Y | 186 mph | 
| R | 106 mph | 
| T | 118mph | 
| H | 130 mph | 
| W | 168 mph | 
Z-speed rated tires originally reflected the hightest speed rating. When new cars were developed that could exceed this speed, the automotive industry added the W and Y rating. While a Z-rating still often appears, such as : 215/50ZR16 91W ... the Z in the size signifies a maximum speed capability in excess of 149 mph; the W in the service description indicates the tire’s 168 mph maximum speed. When the Y-rating in a service description is enclosed in parentheses such as 285/35ZR19 (99Y), the top speed of the tire has been tested in excess of 186 mph.