What Do Tire Numbers Mean?

The last time you checked your tires’ treads or air pressure, or if you’ve had to order new ones from your local Racine, WI tire shop, you’ve probably seen the combination of letters and numbers on their sidewalls. You might have wondered, “What do the numbers on tires mean?” and been unsure of who to ask. Luckily, the service team at Kenosha Toyota is here to answer your questions and break down tire number meaning on cars! Keep reading to learn more.

What Do the Numbers on Tires Mean?

The numerical code on the sidewall of most tires indicates that particular tire’s size, type, performance properties, and intended purpose. It’s important to match tires to your vehicle and driving habits, both to help the tires last as long as possible and to keep you safe on Waukegan, IL roads and beyond.

Determining Tire Number Meanings by Example

A tire’s code employs a series of letters and numbers to inform you or your Milwaukee service center the size, load index, speed rating, and type of tire your vehicle needs for best performance. The easiest way to explain is by using an example:

P215/65R15 95H

Each section of this code means something different to the trained eye, and put together, the entire thing gives all the information needed to fully identify the tire.

Decoding P

In the above code, P stands for P-metric tire, a type of tire used on passenger vehicles like sedans, minivans, and the like. Other tire codes include LT, which stands for light truck. The tire might also lack a letter in the beginning—in this case, it’s a Euro-Metric tire, which is a different system for measuring load capacities.

Decoding 215

The first number in a tire’s code—in this case, 215—stands for the tire’s width, in millimeters, from sidewall to sidewall. So our example tire is 215 mm wide at its widest.

This number is separated from the next with a forward slash.

Decoding 65

The next component to the tire number meaning is its aspect ratio code, which in our example is 65. A tire’s aspect ratio is the ratio between its cross-section height to its width, so in our case 65 indicates that its height is 65% of its width. A bigger aspect ratio translates to bigger sidewalls.

Decoding R

Next up, you see a letter indicating the tire’s construction type. Examples of construction types include

• R, the most common type, indicates radial construction
• B, for bias-ply construction
• D, for diagonal construction

As you can see, our example tire has been radially constructed.

Decoding 15

After the construction type indication, the code notes the rim diameter in inches. This is the size of the wheel that the tire will fit—in this case, the tire will fit a 15-inch wheel.

Decoding 95H

Finally, 95H indicates the tire’s load index and speed rating.

The load index is a measure of how much weight the tire can support when properly inflated. For passenger vehicles, this number is typically between 75–105.

The speed rating is a letter between A–Z indicating how fast the tire can safely go, based on its load capacity. In our example tire, the H indicates that it can safely reach a maximum speed of 130 miles per hour.

How to Check Tire Pressure

Regardless of your tire number meaning, one of the best ways to keep your tires in good health on Waukegan, IL roads is to keep them properly inflated. Checking your vehicle’s tire pressure manually is quick and easy, and most newer vehicles have a Tire Pressure Monitoring System (TPMS) that will automatically warn you if the tire pressure is outside of an acceptable range. If your vehicle’s tires are over- or under-inflated, you’ll receive a notification from the TPMS and can take it to a service station for a top-off. Of course, we’ll also check your tires’ pressure and top them off with air when you come in for a service visit!

Turn to Kenosha Toyota for All Your Maintenance Needs

Whether you need new tires, brakes, or a routine oil change, turn to Kenosha Toyota for all of your maintenance and parts needs! We make it easy to make an appointment on our site — just fill out our schedule service form and our service technicians will be in touch! You can also contact us online with any questions, like What do tire numbers mean? and more.