What Do Tire Numbers Mean?

Maybe you’ve checked your tires or had to order new ones from the local parts shop in %%Target_city_1%%, and on the sidewall you’ve seen a combination of numbers and letters. So, what do the numbers on tires mean? This code is actually simpler than it may seem: It tells you the official size, type, and performance purpose of the tire. Learn how to decode tire numbers from the Mercedes-Benz of Modesto service team below.

Tire Number Meanings

The numbers on your tire are known as a tire code. This sequence of numbers and letters can tell you or your Stockton service center about the size, load index, speed rating, and type of tire your vehicle needs for ideal performance. Here are some examples:

Example: P215/65R15 95H

Right now, this combination of numbers and letters may look like gibberish, but after reading our guide, you’ll see that this code is full of information.

Decoding “P”

The initial letter indicates the use of the tire.“P” stands for “P-Metric tire,” a type of tire that is used for passenger vehicles. If instead the letters were “LT,” that would stand for “light truck,” and the tire would be intended for light-weight pickup trucks. In cases where a letter doesn’t precede the code, then it is a European style tire, or Euro-Metric tire. These kinds of tires have different load capacities.

Decoding “215”

After the “P” we see the number “215”. So, what do the numbers on tires mean? This number is the tire width in millimeters from sidewall to sidewall. That means that in our example, the width of this tire is 215 millimeters.

Decoding “65”

This tire number’s meaning is the aspect ratio code. In this case, it’s “65.” A tire’s aspect ratio is the ratio of the height of the tire’s cross-section to its width. In our example, the tire has an aspect ratio of .65 or 65%. In other words, the tire is 65% as high as it is wide. 

Decoding “R”

The next letter indicates the construction of the tire. “R” stands for radial. 

Decoding “15”

After the “R” comes “15”. This tire number’s meaning is the wheel size from one end to the other. It lets you or the mechanic in Stanislaus know what tire can fit on this particular wheel. A “15” means that the tire is meant for a 15-inch wheel.

Decoding “95H”

The end of the code is the number-letter combination “95H.” This indicates the load index and speed rating of the tire. The load index (“95” in this instance) is how much weight the tire can support when it’s properly inflated. In passenger vehicles it ranges from 75-105. The letter “H” stands for the speed rating. That’s how fast the tire can safely go based on its load capacity. A letter that’s later in the alphabet represents a higher speed. A tire with an “H” rating can reach a maximum speed of 130 mph.

Mercedes-Benz of Modesto Can Answer Your Service Questions

Now that you know what tire numbers mean, you can find answers to more of your car-related questions from Mercedes-Benz of Modesto. Our service experts in Modesto are happy to answer any questions you may have if you contact us online or on the phone or if you stop by for a visit. If you can’t solve the problem yourself, then schedule service with us and we’ll be happy to assist.