What Do the Numbers on Tires Mean?

 
What exactly do tire numbers mean? You’re probably wondering that right now if you find yourself on this page. Well, we here at Ryan Honda of Minot can offer answers! Simply put, tire numbers tell you about the tire size, type, and performance purpose. Of course, we’re referring to number codes like “P215/65R15 95H”. You’ll also find “DOT” 4-number codes that tell you when the tire was manufactured. Ready to learn more? Read on or contact our service center now!

All About Tire Number Meaning

What’s in a tire number? The meaning of tire numbers like P235/55R18 90H or P215/65R15 95H is determined by what each cluster of numbers denotes. In order, the above sequences tell you about:

1. Tire size
2. Tire load index
3. Tire speed rating
4. The type of tire your vehicle needs for maximum performance

Take this code as an example:

Let’s Decode Tire Numbers One by One

Want to figure out what each segment of the tire numbers listed above means? Let’s take P215/65R15 95H as an example.

Decoding “P” – Load Capacity

The “P” stands for “P-Metric tire.” That means these tires are used for a passenger vehicle. Other letters include:

• LT: for “light truck”
• No letter preceding the code: European style tires, aka Euro-Metric tires, have different load capacities and no letter in front of the numbers.

Decoding “215” – Width

Following the “P” is the “215” number, which tells you the tire width in millimeters from one end of the sidewall to the other. In this case, the tire in question is 235 mm wide.

Decoding “65” – Aspect Ratio

After the forward slash, you’ll see a number that tells you the tire’s aspect ratio. What is a tire’s aspect ratio? It tells you the height of the tire’s cross-section as it relates 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” – Construction

The “R” tells you about the tire’s construction. “R” tells you that this is a radial tire.

Decoding “15” – Wheel Diameter

The 15 tells you that this tire fits on a 15-inch wheel.

Decoding “95H” – Load Index & Speed Rating

At the end of the code is “95H,” which tells you two things:

• The load index of the tire

• The speed rating for the tire

The load index (“95” in this instance) tells you how much weight the tire can support when it’s properly inflated. Generally, this number can range from 75-105 for passenger vehicles.

“H” tells you the speed rating, which is how fast the tire can safely go based on its load capacity. This is a letter from A-Z. A tire with an “H” rating can reach a maximum speed of 130 mph.

A Note on Tire Pressure

Now that you know the answer to the question “What do tire numbers mean?” you should know that there’s more to understanding tires than just knowing about tire number meaning. Tire pressure is another important thing to know about.

You should always be sure to drive on tires that aren’t just the right size, load and speed rating, and load capacity for your vehicle, but also inflated to the right pressure. Most Honda vehicles now include a Tire Pressure Monitoring System (TPMS) to help with this. 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 bring it to our service center!

Ryan Honda of Minot Can Help with Your Tire Maintenance Needs!

What do the numbers on tires mean? Now you know! But there is a myriad of other service questions you probably will have during your Honda ownership experience. Luckily, we’re here to help with them all via our service tips! Looking for new tires? We can help with that, too!