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Have you ever wondered what all the letters and numbers on the sidewall of your tire mean? The numbers may not seem like much but they can tell you a lot more than just the size of your tire.

Have you ever wondered what all the letters and numbers on the sidewall of your tire mean? The numbers may not seem like much but they can tell you a lot more than just the size of your tire. You’ve probably seen all the letters and numbers on the sidewall of your tire and wondered, “what do they mean?” The numbers may not seem like much but they are actually pretty helpful. This seemingly complex code can tell you more than just the size of your tire. Here are a few tips to help you understand what it all means.

Tire Type

[P]215/65 R15

The letter at the beginning of the tire size tells us the class of tire we are dealing with. There is P for passenger car, LT for light truck, or no letter at all, which indicates a Euro metric tire.

Tire Width

P[215]/65 R15

The first three-digit number is the width of the tire measured in millimeters from one sidewall to the other. In this example, the tire is 215 millimeters wide.

Aspect Ratio

P215/[65] R15

The two-digit number after the slash is the tire’s aspect ratio. This is a comparison of the tire’s height versus width, which gives us the height of the sidewall. A number of 65 means the height of the sidewall is 65% of the width of the tire. The higher the aspect ratio, the bigger the tire’s sidewall will be.

Construction

P215/65 [R]15

The R in this example stands for radial construction. Most tires today are built using radial construction. For more information on tire construction comparisons click here.

Wheel Diameter

P215/65 R[15]

The last two-digit number specifies the size of the wheel the tire is built to fit. This is measured in inches. The tire example provided is made to fit a 15-inch wheel.

Load Index and Speed Rating

Your tires will also give you a load index and speed rating. The load index indicates the maximum load capacity that your tire can support. The speed rating gives you the maximum speed capability for your tire. Speed ratings are represented by letters ranging from A to Z. For example, a tire with a speed rating of Z will have the highest speed rating. Regardless of tire rating, it is advised not to exceed posted speed limits. Do you have questions regarding your tire’s specifications? Do you have other markings on your tire that you’re curious about? Give us a call or send us an e-mail and one of our friendly staff members would be happy to assist you!

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