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You might not realize it just looking at them, but your tires contain a wealth of information! But how exactly are you supposed to read it?

When you look at your tires’ sidewalls, there’s a whole bunch of stuff written there besides just “Goodyear”. But what does it all mean?

Reading the information on a tire’s sidewall is essential for understanding its specifications and ensuring that it meets the requirements for your vehicle. Here’s a guide on how to decode the information on a tire’s sidewall:

 

 

 

• Tire Size:
  • The tire size is usually presented in a standardized format, such as P215/65R15. Here's how to interpret this:
    • P: Stands for passenger car.
    • 215: Stands for the tire's width in millimeters.
    • 65: Indicates the aspect ratio, which is the ratio of the tire's height to its width (65% of the tire's width in this case).
    • R: Denotes radial construction.
    • 15: Represents the diameter of the wheel in inches.

                                                               

• Load Index:
  • The load index indicates the maximum weight the tire can support. It is represented by a numerical value. A load index chart is typically available to help you find the largest load ability in pounds or kilograms for a specific index.

                                                                 

• Speed Rating:
  • The speed rating shows the maximum speed at which the tire can carry a load safely. It is represented by a letter (e.g., H, V, W). Each letter corresponds to a specific speed range, and you can refer to a speed rating chart to find the corresponding maximum speed.

                                                                

• Tire Construction:
  • The construction type is usually shown by the letters "R" (radial) or "D" (diagonal). Most modern tires are radial, as radial construction supplies better performance and fuel efficiency.

                                                               

• DOT Code:
  • The Department of Transportation (DOT) code is a series of numbers and letters that includes information about the tire's manufacturing plant, size, and date of production. The last four digits of the DOT code indicate the week and year of manufacture. For example, if the2219 code ends in "2219," it means the tire was manufactured in the 22nd week of the year 2019.

                                                          

• Tire Ply Composition and Material:
  • The sidewall may also include information about the tire's ply composition and materials used in its construction. For example, "4PLY" indicates a tire with four layers of material.

                                                       

• Maximum Cold Inflation Pressure:
  • The maximum cold inflation pressure is the highest pressure the tire should be inflated to when it's cold. It is usually expressed in pounds per square inch (psi).

                                                  

 

Reading the information on your tire’s sidewall is crucial when replacing tires or understanding their capabilities. Make sure to choose tires that meet the specifications recommended by your vehicle manufacturer to ensure optimal performance, safety, and longevity. If you have any doubts or need further clarification, consult your vehicle’s owner’s manual or talk to one of the professional techs at your local Schierl Tire & Auto Service!