Tire speed rating chart

Toyo defines the speed symbol as the speed at which a tire can carry the load corresponding to its load index under manufacturer-specified service conditions. Michelin places it next to the load rating in the tire’s service description.

Bridgestone says the speed rating is usually the last item in the tire code. In its example P205/60R16 82S, S is the speed rating; the adjacent number is explained in the load index guide.

Bridgestone says ratings come from laboratory testing with simulated speeds and loads. Actual speed capability may be lower because of inflation, wear, vehicle condition, driving conditions and the duration of sustained speed.

Use the chart to match the tire’s symbol to its published speed. Toyo lists Q at 99 mph (160 km/h), R at 106 mph (170 km/h) and S at 112 mph (180 km/h).

Toyo lists T at 118 mph (190 km/h), H at 130 mph (210 km/h) and V at 149 mph (240 km/h). Read the listed value rather than assuming every letter follows alphabetical order.

Westlake says a tire capable of more than 149 mph may carry Z in its size designation, as in 245/40ZR18. Bridgestone says manufacturers may insert Z into the size description of W- or Y-rated tires.

Toyo lists W at 168 mph (270 km/h) and Y at 186 mph (300 km/h). These speed symbols appear in the service description, separate from ZR in the size.

Toyo lists (Y) as 195 mph. For a specific Z-rated tire, Bridgestone advises contacting the manufacturer for its speed capability.

Michelin says replacement tires should meet or exceed the vehicle manufacturer’s specified speed rating. Bridgestone says to find that recommendation in the owner’s manual or on vehicle placards, such as the driver’s door jamb.

Bridgestone advises choosing the specified speed rating and keeping the same rating on all four tires. Continental also recommends the same speed rating at every wheel position.

Michelin says speed ratings reflect structural integrity and heat resistance, not just top-speed capability. Bridgestone emphasizes that a speed rating is not a recommended travel speed.