Speed ratings for tires are identified by means of a speed symbol shown on the sidewall of a tire. Although a tire may be speed rated, tire manufacturers do not endorse the operation of any vehicle in an unsafe or unlawful manner. Furthermore, tire speed ratings do not imply that a vehicle can be safely driven at the maximum speed for which the tire is rated, particularly under adverse road and weather conditions or if the vehicle has unusual characteristics.
Speed ratings are based on laboratory tests which relate to performance on the road, but are not applicable if tires are under-inflated, overloaded, worn out, damaged or altered.
Example: Tire size P215/60R15 H 185/65 R 15 H: the H indicates a maximum permitted speed of 130 mph.