What Do Tire Numbers Mean?

If you’ve ever checked your tires or if you’ve had to order new ones from your local Round Rock tire shop, you’ve more than likely seen the combination of numbers and letters on the sidewall of them. So, you’re probably wondering, “What do tire numbers mean?” This code indicates the size and type of tire it is, and its particular performance purpose. If you’re in need of new tires and need to determine which ones to get, or if you’re simply wondering what the numbers on tires mean, let Covert Buick GMC Austin teach you. And don’t forget to check out our tire store! 

Determining Tire Number Meanings

A tire’s code uses a series of letters and numbers in order to inform you or your Austin service center of the size, load index, speed rating, and type of tire your vehicle needs for maximum performance. Take this code for example:

Example: P215/65R15 95H

While it may seem like gibberish, each section of code represents a piece of information to correctly identify the type of tire it is.

Decoding “P”

The “P” stands for “P-Metric tire,” meaning that it is used for passenger vehicles. If your tires read “LT,” this stands for “light truck,” and the tire is intended for light-weight pickup trucks. If the tire does not have a letter preceding the code, it is a European-style tire, or Euro-Metric tire, which has different load capacities.

Decoding “215”

Following the “P” is the “215” number, which stands for tire width in millimeters from sidewall to sidewall. So in our example, the width of this tire is 215 millimeters.

Decoding “65”

After the forward slash comes the aspect ratio code, indicated in our example by “65.” A tire’s ratio is the height of the tire’s cross-section to its width, so in our example, this tire has an aspect ratio where its height is equal to 65% of the tire’s width. The bigger the aspect ratio, the bigger the sidewalls will be.

Decoding “R”

The “R” indicates the tire’s construction, with “R” representing that it’s a radial.

Decoding “15”

“15” indicates the wheel size from one end to the other, which informs us of what tire can fit on this particular wheel. This code tells us that this tire is meant for a 15-inch wheel.

Decoding “95H”

At the end of the code is “95H,” which is the load index and speed rating for the tire. The load index (“95” in this instance) indicates how much weight the tire can support when it’s properly inflated and can range from 75-105 for passenger vehicles. “H” represents the speed rating, which is how fast the tire can safely go based on its load capacity. This rating is ranked by various letters. In our example, a tire with an “H” rating can reach a maximum speed of 130 mph.

How to Check Tire Pressure

Regardless of the size of your car’s tires, one of the best ways to keep them in good health on Round Rock roads is to keep them properly inflated. Checking your vehicle’s tire pressure is quick and easy, as nowadays, most new vehicles have a Tire Pressure Monitoring System (TPMS). If your vehicle’s tires are over- or under-inflated, you’ll receive a notification from the TPMS. You can take your vehicle to a gas station to top off the air in the tires, or we’ll do it for you when you come in for a service visit! 

Turn to Covert Buick GMC Austin for All Your Maintenance Needs

If you are in need of new tires or brakes or are ready to come in for your regularly scheduled oil change, turn to Covert Buick GMC Austin for all of your maintenance and parts needs! Complete this secure schedule service form to make an appointment in Austin. Complete this form by entering in your VIN and basic contact information, so our service technicians can best service your Buick, GMC. If you have any questions, contact us online.