Tire speed rating: what do the letters mean?

The speed rating is a letter that shows the maximum speed a tire can safely handle. You'll find it at the end of the size code on the tire's sidewall. In 205/55 R16 91V, for example, the speed rating is V, which means the tire is rated for speeds up to 240 km/h.

Speed rating chart

Each letter stands for a specific speed limit. The later the letter comes in the alphabet, the higher the limit. The one exception is H, which for historical reasons sits between U and V.

Some tires carry a ZR marking, as in 245/40 ZR18. It marks tires designed for speeds above 240 km/h. On these tires the exact limit is usually given by the W or Y next to it. A (Y) in parentheses means a limit above 300 km/h.

How do you choose a speed rating?

• Don't go below the rating your car's manufacturer recommends. You'll find it on the placard by the driver's door or in the owner's manual.
• A higher rating is fine. It poses no safety problem; such tires just tend to cost a little more.
• Winter tires may be rated one step lower. If yours are, keep your speed within the tire's own limit.
• The limit applies to factory test conditions. A worn, damaged or underinflated tire may not hold up to it.

Read the speed rating together with the load index

In the 91V part of the size code, 91 is the load index and V is the speed rating. You'll find what the number means in the load index chart. We explain the rest of the size code in our guide to reading tire sizes, and for every other marking, see our guide to tire sidewall markings.

If you know your size, compare prices for tires in that size on the tire search page. If you don't, use our vehicle search to find the factory-recommended tire sizes for your make and model.