What Do Tire Numbers Mean?

Have you ever looked at a tire or had to order new ones from Louisville? You must have noticed all those numbers and letters on the sidewall. You might have wondered, “What do tire numbers mean?” The numbers and letters on a tire’s sidewall provide important information about the tire’s size, load capacity, speed rating, and construction. Below, our Cross Chrysler Jeep FIAT service techs will help decode those numbers and letters so you can be an informed shopper the next time you need new tires for your vehicle.

Different Tire Number Meanings

A tires code is made up of numbers and letters to inform you or Louisville about the features of your tire. This can be useful when shopping for new tires or if you need to know how fast you can go or how much weight your tire can carry. Tires are classified according to their intended use: passenger car tires, light truck tires, commercial truck tires, off-road tires, and racing slicks. Each type of tire has its own set of sizing standards.

Example: “P215/65R15 95H”

The tire code above means that this tire has the following features:

“P”

In our example, the “P” means the tire is a passenger car tire. If the tire were a light truck tire, the code would start with an “LT” instead of a “P.” If there is no letter before the first number in the code, it is a European metric tire. 

“215”

The number “215” indicates that this is a 215-millimeter-wide tire. The width is measured in millimeters and corresponds to the width of the tread from sidewall to sidewall. In general, wider tires provide better stability and handling, while narrower tires are lighter weight and can improve gas mileage.

“65”

The number “65” after the slash mark indicates that this tire has an aspect ratio of 65. This figure gives the relationship of the tire’s sidewall height to the width of the tread. In this case, the sidewall is 65% as tall as the tire is wide. A lower aspect ratio like 60 or 55 indicates a shorter sidewall, and a plus sign (+) before the two-digit number means an extra-tall sidewall.

“R”

The letter “R” after the aspect ratio denotes radial construction. Radial tires are made with steel belts running around their circumference for strength under high speeds and temperatures. The other type of construction used for passenger car tires is called bias-ply, in which the tire’s body is made with layers of crisscrossing fabric. Bias-ply tires are not as common as radial tires.

“15”

The number “15” after the “R” denotes the diameter of the wheel rim in inches. In this case, it would take a 15-inch diameter wheel to fit this tire.

“95H”

A load index is a number that corresponds to the maximum weight that the tire can support when properly inflated. The higher the load index number, the greater amount of weight your tire can carry. The speed rating tells you how fast you can go without damaging the tire. The speed rating is represented by a letter, and the highest rating you’re likely to see on a passenger car tire is “H,” which corresponds to a top speed of 130 mph.

Turn to Cross Chrysler Jeep FIAT for All Your Maintenance Needs

As you can see, there is a lot of information in those numbers and letters on your tires’ sidewalls. That’s why Cross Chrysler Jeep FIAT shares a variety of service tips and tricks— so that you can be a more informed shopper. If you’re looking for new tires, our experts at Cross Chrysler Jeep FIAT can help you choose the right Jeep tire size for your vehicle and driving needs. Contact us today to speak with a tire specialist!