What Do Tire Numbers Mean?

What Do Tire Numbers Mean?

The numbers on the sidewall of every tire informs you or your San Rafael service center of that tire’s speed rating, size, construction, type, and more. The best way to break down the tire code is to use an example:

P215/65R15 95H

Each piece of the code above indicates a different aspect of the tire. Below, we’ll show you what each of these aspects are so that you can apply your knowledge to other tires you find in the wild.

Tire Number Meaning: Decoding P

The P above stands for P-metric tire. P-metric tires are made for passenger vehicles, like sedans, minivans, and SUVs, and are built for smooth driving and long-lasting tread. Another common designation is LT for light truck, which indicates a tire built for heavier loads or off-roading. Your tire might also lack a letter at the front, in which case it’s a Euro-metric tire. Euro-metric tires are similar in use to P-metric tires, but are built with different load capacities.

Tire Number Meaning: Decoding 215

The next number, 215, shows the tire width in millimeters. This means that our example tire measures 215 millimeters wide, or a little under 8 ½ inches.

Tire Number Meaning: Decoding 65

A forward slash separates the tire width and the next number, the aspect ratio code. A tire’s aspect ratio is found by dividing the tire’s cross-section height by its width, then multiplying that number by 100. This means that our example tire is 65% as tall, measured from the inside rim to the outside, as it is wide.

Tire Number Meaning: Decoding R

Most tires you’ll see around Mill Valley will carry an R designation, meaning the tire has a radial construction. While there are other construction types, R is by far the most common type on modern tires.

Tire Number Meaning: Decoding 15

Next up, a number indicating the tire’s rim diameter in inches. In our example, the tire will fit on a 15-inch wheel—so make sure this number matches your car!

Tire Number Meaning: Decoding 95H

Finally, the tire code has a section for its load index and speed rating. The load index— 95 in this case—indicates how much weight the tire can support when properly inflated. For most passenger vehicles, this number will range between 75–105. The speed rating—for our example, H—indicates how fast the tire can safely travel for any length of time. On this tire, H indicates a maximum safe speed of 130 mph.

How to Check Tire Pressure

Regardless of your tires’ rating, size, or age, one of the best things you can do to ensure their longevity is keeping them properly inflated. Checking your tire pressure manually is quick and easy, but nowadays most new vehicles include a Tire Pressure Monitoring System (TPMS) that can alert you when it detects over- or under-inflation. When you get a notification from your TPMS, it’s time to top off your tires at a gas station—or we’ll top them off when we perform regular maintenance on your Honda at our San Rafael service center!

For All of Your Maintenance Needs, Marin Honda is Here for You

Whether you need new tires or just a rotation, or even regular maintenance like an oil change, the service team at Marin Honda is standing by to help with all of your maintenance and parts needs. We make it easy to schedule an appointment online at our service center near San Francisco, plus we make it easy to save on necessary service with our rotating service specials! Contact us any time with questions or concerns, and we’ll be happy to help.