What Do Tire Numbers Mean?

If you’ve ever taken a close look at your GMC or Buick tires, you’ve probably noticed a long combination of letters and numbers on the sidewall. What do these tire numbers mean? In short, each letter and number indicates something different — together, the combination defines the tire’s size, type, purpose, speed rating, and more. As a qualified Buick and GMC service center, Hendrick Buick GMC Cary has everything you need to know about the numbers on Buick and GMC tires in the guide below. Check it out!

Determining a Tire Number Meaning

As discussed above, the code you see on the side of your tire is a combination of several different letters and numbers that indicate different things. Let’s take a look at an example:

Example: P215/65R15 95H

This may look like gibberish at first, but each section of the code indicates something different about your tires. We’ll break it down piece by piece below. 

Decoding “P”

The first letter in the code, P, stands for “P-Metric tire.” This means that the tire is rated for passenger vehicles. If you drive a pickup truck in Raleigh, you might see LT instead of P, which stands for “light truck.” If you examine your tires and don’t see an initial letter, then your tires are Euro-Metric, which have different load capacities.

Decoding “215”

The next thing we see is 215, which stands for the width of the tire from sidewall to sidewall — in this case, 215 millimeters.

Decoding “65”

After the tire width comes a forward slash, designating the next line of the code, which is the aspect ratio of the tire’s height to its width, which in this case is 65%. A bigger aspect ratio means bigger sidewalls.

Decoding “R”

The letter R after the aspect ratio means that the tire’s construction is a radial.

Decoding “15”

After the letter R is another size indicator, this time the size of the wheel in inches from one end to another — this informs us which tire can fit on this particular wheel (15 inches).

Decoding “95H”

The last combination in the code is 95H, which indicates the tire’s load index and speed rating. A tire’s load index indicates how much weight it can support when properly inflated—95 in this case—while the speed rating is an A-Z ranking that indicates how fast the tire can go. An H rating indicates a maximum speed of 130 miles an hour.

How to Check Tire Pressure 

Whatever size your tires may be, making sure they’re properly inflated is key to keeping you safe on the Apex roads. You can check your tire pressure pretty easily since most new vehicles come with a built-in Tire Pressure Monitoring System (TPMS) that will alert you if there’s something wrong with your tires’ inflation. If this is the case, you can take your car to the nearest gas station’s tire filling station, or schedule a service appointment with Hendrick Buick GMC Cary and we’ll get you taken care of!

Turn to Hendrick Buick GMC Cary for All Your Maintenance Needs

If you have any questions about your tires or want to learn more about the services we at Hendrick Buick GMC Cary offer, contact our office today! You can also bring your car by our Holly Springs-area service center if you want to talk to an expert in person. And if you’re looking to save on your next appointment, we offer service specials updated all the time.