Tire speed ratings indicating the maximum speed at which the tire can carry a load corresponding to its load index under specified service conditions.
What is Tire Speed Rating?
Tire speed rating specifies the optimal speed that the tire can safely maintain over a period of time. It is the fastest speed a tire can handle before compromising its designed performance. The higher the speed rating, the better control and handling you have at higher speeds. The speed rating system was designed to control tire safety and performance at standardized speeds. Tire speed rating is given a letter from A (3 mph) to (Y) (195 mph).
Where Can I Find My Tire Speed Rating?
Tire speed rating is imprinted on tire sidewall as a part of the tire size service description right after tire load index. For your vehicle's original equipment tire speed rating, look in the owner’s manual, driver’s side doorjamb, glove box door, or gas tank hatch.
Recommended High Speed Tire Pressure and Tire Load Capacity Adjustments
When driving at high speeds, tires are subjected to tremendous stress as tire revolutions per second increase significantly with faster speed. To accommodate higher speeds you need to make adjustments to the tire pressure recommended by the vehicle manufacturer and to the tire's maximum load capacity branded on the tire sidewall. Start with tire pressure recommended for normal driving conditions, and as speed increases, initially so does the tire inflation. When tire inflation reaches its maximum allowed then tire load capacity is reduced as speed increases.
Never exceed the maximum cold inflation pressure branded on the tire's sidewall.