W speed rating
W at the end of a tire’s service description, as in 93W, is the speed rating for 270 km/h (168 mph).
How to read it
On the chart used by USTMA and Bridgestone, W is 270 km/h (168 mph), between V at 240 km/h (149 mph) and Y at 300 km/h (186 mph). Michelin and BFGoodrich give W as 168 mph. BFGoodrich says W and Y were added above Z to match the speeds of exotic sports cars. See the full chart.
Also searched as: W rated tire.
What each marking means under the standard that defines it. This page describes markings; it doesn’t advise on choosing, fitting, inflating or replacing tires.
W with or without ZR
Because a W tire is rated above 240 km/h (149 mph), its size may include a Z. USTMA and Bridgestone give P275/40R17 93W and P275/40ZR17 93W as the same speed rating, 168 mph; P275/40ZR17 with no service description is only known to be over 149 mph, and they refer to the tire’s maker for the figure. See ZR in a tire size.
More tire sidewall markings
Browse symbols drawn with curves and waves or letters and numbers.
Sources
- Tire Care and Safety Guide, U.S. Tire Manufacturers Association (USTMA), Speed Symbol, p. 8
- Replacement Tire Selection Manual, Ref. No. P-06-01, August 2006, Bridgestone Americas, p. 7
- Tire Load Rating & Speed Rating Explained, Michelin North America, FAQ
- Tire Speed Rating Chart & Tire Tread Life, BFGoodrich Tires (Michelin North America), Speed rating; FAQ
- Speed and Load Rating Charts Explained, Bridgestone Australia, Tyre speed symbol table
Last reviewed September 29, 2026 by Rory Hansen. How we research