During the process of inspecting your tires or when purchasing a brand new set, there’s a good chance that you have noticed a combination of numbers and letters on the sidewall. Because of this, you may have asked, “What do tire numbers mean?” This code indicates the size and type of tire it is and its particular performance purpose. When you are in the market for a set of brand new tires and need to figure out the type that your vehicle requires, Auffenberg Dealer Group near O'Fallon has the details.

The Key to What Tire Numbers Mean

A tire’s code is made up of a series of letters and numbers. This lets you know its size, load index, speed rating, and type of tire. It makes shopping for new tires much easier. Here is an example of what a tire code may look like:

P215/65R15 95H

This may look a bit complicated, but once you know what each section means, it should all make sense. Each section of code represents a piece of information to correctly identify the type of tire it is.

• The “P” stands for “P-Metric tire,” meaning that it is used for passenger vehicles. Your tires could also say “LT,” which designates “light truck.” It is possible that your tires do not have a letter that comes before the code. If so, that means you have a European style tire or Euro-Metric tire. These tires have different load capacities.
• Following the “P” is the “215” number, which lets you know how wide the tire is from sidewall to sidewall. In this case, it would mean the tire is 215 millimeters wide.

After the slash is where you will find the aspect ratio code. It is the number “65” in the sample above. How is a tire’s ratio determined? It’s the ratio of the height of the tire’s cross-section to the width. If you look at the previous example, you will see the aspect ratio shows the height is equal to 65% of the tire’s width. Tires with bigger sidewalls will have a larger aspect ratio.

• The “R” indicates the tire’s construction, with “R” representing that it’s a radial.
• The next number, in this case, “15,” tells you the wheel diameter. The code in the example shows that this tire is for a car that has a 15-inch wheel.

The last part of the code is the tire’s load index and speed rating. In the example, it is “95H.”

• “95” is the load index. What is the load index? When your tire is inflated to the proper level, this number tells you how much weight it can support. For passenger vehicles, this number will be anywhere from 75-105.
• “H” designates the speed rating. Here you will find out how fast you can go with the set of tires that you have. This rating is ranked from A-Z. A vehicle with an “H” rating, like the example, can safely travel up to 130 mph.

Learn More About Tires with Auffenberg Dealer Group

If your vehicle is in need of new tires, or you have questions about your tires, do not hesitate to reach out to Auffenberg Dealer Group. We would be glad to answer all of your parts and service inquiries.