What Are Tire Ratings?
Tire ratings are part of the standardized information molded into the tire sidewall. These alphanumeric markings provide key details about the tire’s dimensions, construction, and operating limits.
Among these markings, the load rating and speed rating form what is known as the tire’s service description. This information is used by vehicle manufacturers to specify which tires are suitable for a given vehicle.
You can also find recommended tire ratings:
On the vehicle tire placard (usually located on the driver’s door pillar)
In the vehicle owner’s manual
When replacing tires, these ratings should always be checked and respected.
Understanding Tire Markings
A typical tire sidewall marking may look like this:
205 / 55 R 17 91 V
This code provides the following information:
205 – Tire width (in millimetres)
55 – Tire height as a percentage of width
R – Radial construction
17 – Rim diameter (in inches)
91 – Tire load rating
V – Tire speed rating
Tires with the same dimensions may have different load or speed ratings. This is why it is important to understand both ratings before replacing your tires.
Tire Load Rating
What Is the Tire Load Rating?
The tire load rating (also called the load index) is a numerical code that corresponds to the maximum load a single tire can carry when properly inflated. Load ratings are defined by standardized tables used throughout the tire industry.
The load rating of a tire must always meet or exceed the value specified by the vehicle manufacturer.
How to Find Your Tire’s Load Rating
You can find the load rating:
On the tire sidewall, as part of the service description
On the vehicle tire placard
In the vehicle owner’s manual
Once identified, the corresponding maximum load can be found in a standardized load index chart.
What Does XL (Extra Load) Mean on Tires?
Some tires are marked XL, which stands for Extra Load. These tires are reinforced to carry higher loads than standard tires of the same size when inflated to higher pressures.
Extra Load tires are commonly specified for heavier vehicles, such as SUVs and certain passenger vehicles, where additional load capacity is required.
Can I Switch to a Tire With a Higher Load Rating?
When replacing tires, Michelin recommends fitting tires that match the original manufacturer’s specified dimensions and load rating.
It is permitted to install a tire with a higher load rating. However, this does not increase the vehicle’s allowable load. The maximum permissible load remains limited by the vehicle’s axle load rating, regardless of the tire’s capacity.
Tire Speed Rating
What Is the Tire Speed Rating?
The highest speed at which a tire can support its maximum load under particular circumstances is defined by the tire speed rating, which is represented by a letter. In the tire's service description, the speed rating is listed next to the load rating.
For instance, a tire with the number 91V has a speed rating of V and a load rating of 91.
When properly inflated and loaded, a V-rated tire can withstand speeds of up to 240 km/h (149 mph).
How to Find Your Tire’s Speed Rating
The Speed Rating Can Be Found:
On the tire sidewall
On the vehicle tire placard
In the vehicle owner’s manual
When replacing tires, the speed rating should always meet or exceed the vehicle manufacturer’s specification. Learn more on tire mixing here.
Can I Switch to a Tire With a Higher or Lower Speed Rating?
It is possible to add tires with a speed rating higher than what was originally specified.
Installing tires with a lower speed rating is not advised unless they are winter-capable, such as Winter or All-Season tires with the 3PMSF emblem. In these situations, the driver has to make sure the vehicle speed doesn't go over the maximum rated speed of the tire.
Why Load and Speed Ratings Must Be Respected
Load and speed ratings define the operating limits of a tire. Exceeding these limits can generate excessive heat, which may affect durability and increase the risk of tire damage.
To ensure proper fitment and safe operation, Michelin recommends consulting:
The vehicle tire placard
The owner’s manual
A trained tire professional
Simplified Load and Speed Ratings With MICHELIN CrossClimate
The MICHELIN CrossClimate all-season range provides a single load and speed rating for each tire size to make tire choosing easier. These ratings are intended to provide performance in both summer and winter climates while meeting typical load and speed requirements for that dimension.
Explore Michelin’s tires to find options designed to match your vehicle’s specifications and driving needs.
FAQ
Tire Load Index and Speed Rating Explained
The tire load rating indicates the maximum weight a single tire can carry when properly inflated, while the speed rating indicates the maximum speed the tire can sustain at that load. Both ratings are part of the tire’s standardized service description and must be respected when replacing tires.
Recommended load and speed ratings can be found on the vehicle tire placard (usually located on the driver’s door pillar), in the vehicle owner’s manual, and on the sidewall of the original equipment tires.
Yes. Tires with a higher load rating or higher speed rating than the original specification may be installed. However, installing tires with a higher load rating does not increase the vehicle’s allowable load, which remains limited by the vehicle manufacturer’s specifications.
Tires with a lower speed rating should not be used unless they are Winter or All-Season tires marked with the 3PMSF symbol. In such cases, drivers must ensure the vehicle is not driven beyond the tire’s maximum rated speed.
Load and speed ratings define the operating limits of a tire. Exceeding these limits can cause excessive heat buildup, which may affect durability and increase the risk of tire damage or failure. Following the manufacturer’s specified ratings helps ensure safe and proper tire performance.
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