How to identify a tire's maximum speed rating

A tire's maximum speed rating is marked on its sidewall, alongside other information such as size, load capacity limit, manufacturing date, etc.

This indicator shows the maximum speed associated with the tire, but care is needed: it has no direct relationship with the limits set for each highway or urban road. The maximum speed permitted on the road must be observed as indicated by signs.

For information about each tire's speed, see the answers to some common questions on the subject:

What is a “tire's maximum speed rating”?

The speed rating is represented by a letter and indicates the maximum safe speed that the tire can withstand when used according to the manufacturer's specifications.

In practice, this information should be read alongside other data marked on the tire, such as size and load index. When replacing tires, the technical recommendation is to maintain the same size, load index and speed rating.

Learn about this topic by watching the video we prepared (video in Portuguese):

How to find this information

This information is alongside DOT data, tire size and load capacity limit, all marked on the sidewall. However, we are talking about a letter rather than a number.

Yes, that's right.

You need to find this letter and check which speed in kilometers it represents in the maximum tire speed table. Here are some symbols used in this conversion:

Maximum tire speed table.

What happens if you exceed the tire speed limit?

This rating exists precisely to prevent the tire from being damaged through misuse. Exceeding this speed, in addition to endangering drivers' lives, can cause irreversible tire damage.

Examples include excessive wear, premature casing loss or, in more serious cases, a tire blowout and vehicle damage.

That is also why tires with different speed ratings should not be used. And if this does happen, the lowest maximum speed must always be considered.

In other words, if one tire has a limit of 160km/h and another of 210km/h, you should keep 160km/h as the reference.

How to control a tire's maximum speed

To carry out this type of control, you should start by choosing tires with speed ratings suited to the vehicle and the expected driving conditions.

Keeping a record of this information and communicating it to drivers is also fundamental.

If you want stricter control, you can opt for telemetry and monitoring solutions, which record the average speed used on each route.

Drivers should also pay attention to road speed limits and adjust vehicle speed according to those limits, road signs and weather and traffic conditions.

Keeping tires in good condition, regularly inspecting pressure and checking alignment and balancing also helps prevent excessive wear and failures that can occur when exceeding the maximum recommended speed.

Discover the Prolog App solution for more efficient tire management in your fleet.