What Do the Numbers on Tires Mean?
Tire markings are molded into the sidewall and provide key technical details about the tire. They identify the tire type, size, construction, load rating, speed rating, and other performance or regulatory information.
When replacing tires, understanding these markings helps ensure the new tire meets the specifications recommended by the vehicle manufacturer.
How to Read a Tire Size
A tire size is represented by a sequence of numbers and letters that describe the tire’s dimensions and construction. Additional letters may also appear to indicate the intended application or load capacity.
Common Tire Type Prefixes
P – Passenger car
LT – Light truck
C – Commercial van tire
XL / HL / Reinforced – Tires designed to carry higher loads than standard tires of the same size
T – Temporary spare tire
Tires with reinforced or special load markings should always be replaced with an equivalent specification.
How to Read Tire Width and Aspect Ratio
Example: 205 / 55
205 – Nominal section width of the tire, measured in millimeters
55 – Aspect ratio, representing sidewall height as a percentage of the tire’s width
These values help ensure proper fitment on the wheel and adequate clearance within the vehicle’s wheel well.
How to Read Tire Construction Type and Wheel Diameter
Example: R 17
R – Radial construction
17 – Wheel diameter, measured in inches
Michelin pioneered radial tire construction, which combines flexible sidewalls with a rigid tread structure. This design supports durability, comfort, and reduced rolling resistance.
How to Read the Load and Speed Ratings
Example: 91 V
A number followed by a letter on the tire sidewall represents the tire’s service description.
Load rating (91): The maximum weight a single tire can carry when properly inflated
Speed rating (V): The maximum speed at which the tire can carry that load under specified conditions
These ratings are standardized and must meet or exceed the specifications set by the vehicle manufacturer.
Learn more in our guide to tire load rating and speed rating.
How to Identify the Brand and Tire Line
The tire sidewall always displays the manufacturer’s brand name and the tire line or range.
For example, MICHELIN identifies the brand, while a name such as Pilot Sport 4 S identifies the specific tire line. This information helps distinguish performance characteristics within a manufacturer’s product lineup.
How to Identify Tire Type (Tubeless or Tube Type)
TUBELESS: Indicates that the tire does not require an inner tube
TUBE TYPE: Indicates that an inner tube is required
How to Read Tire Pressure Markings
Sidewall markings such as MAX LOAD and MAX PRESS indicate the maximum load and maximum inflation pressure the tire is designed to withstand. These values are not the recommended operating pressure for your vehicle.
Always refer to the vehicle owner’s manual or the vehicle tire placard to find the recommended inflation pressure specified by the vehicle manufacturer.
How to Read a Tire Date Code
The tire date code is part of the DOT (Department of Transportation) marking on the tire sidewall.
The first two digits indicate the week of manufacture
The last two digits indicate the year of manufacture
For example, 4714 means the tire was manufactured during the 47th week of 2014. Tire age alone does not determine whether a tire is usable; tread wear and overall condition are also critical factors.
How to Tell If a Tire Has Reached Maximum Wear
Tires include built-in treadwear indicators, raised bars located within the tread grooves. When the tread surface wears down to the level of these indicators, the tire has reached the minimum tread depth of 2/32 inch (1.6 mm).
On Michelin tires, treadwear indicators are marked by the Michelin Man symbol on the sidewall to make them easier to locate.
Snow and All-Season Tire Markings: 3PMSF and M+S
3PMSF (Three-Peak Mountain Snowflake) – Indicates the tire has met standardized testing requirements for verified winter performance and is approved for use in regulated winter conditions.
M+S (Mud and Snow) – Indicates the tire is designed for mud and snow conditions based on the manufacturer’s criteria, but does not require standardized winter performance testing.
Only tires marked with the 3PMSF symbol provide verified winter performance.
OE (Original Equipment) Markings
Some vehicles are equipped with tires specifically developed for a particular make or model. OE markings indicate that the tire was designed and approved for original equipment use.
OE tires may be optimized for factors such as handling, ride comfort, noise, rolling resistance, or system compatibility. When applicable, Michelin recommends replacing OE-marked tires with tires that carry the same OE designation.
FAQ
How to Read Tire Sidewall Markings
Tire sidewall markings follow a standardized format that includes size, construction type, load rating, and speed rating. Each marking corresponds to a specific technical characteristic that helps determine tire suitability.
Tire markings are molded into the tire sidewall. Recommended tire specifications are also listed on the vehicle tire placard, typically located on the driver’s door jamb, and in the owner’s manual.
Yes. Tires with the same dimensions may have different load or speed ratings. Replacement tires must meet or exceed the vehicle manufacturer’s specified ratings.
M+S indicates the tire is designed for mud and snow conditions according to the manufacturer. The 3PMSF symbol confirms the tire has passed standardized winter performance testing.
An OE marking indicates the tire was specifically developed and approved for original equipment use on a particular vehicle. When applicable, Michelin recommends replacing OE tires with the same OE specification.
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