What Do The Numbers On My Tires Mean

When you take a closer look at the sidewall of your vehicle’s tires, you’ll notice a series of numbers and letters that might seem like a jumble of information. What Do The Numbers On My Tires Mean? However, these numbers are not random; they convey crucial details about your tires’ specifications and capabilities. 

In this comprehensive guide, we’ll break down the meaning behind the numbers on your tires and help you understand their significance.

What Details Are Mentioned On The Tires?

Many details are mentioned on your tires, such as tire size, load index, and tire construction. These variables are important when choosing the TPMS sensors or new tires. Here are the details present on the tire’s sidewall.

Tire Size

The first set of numbers on your tire’s sidewall typically represents the tire size. This includes the width, aspect ratio, and diameter of the tire. For example, if you see “225/45R17,” the number 225 indicates the width of the tire in millimeters, 45 represents the aspect ratio (the ratio of the tire’s height to its width), and 17 signifies the diameter of the rim in inches.

Load Index

The load index, usually a two- or three-digit number, indicates the maximum weight that the tire can support. A load index of 95, for instance, signifies that the tire can handle a maximum load of 1521 pounds.

Speed Rating

The speed rating indicates the maximum speed the tire is designed to handle safely. This is represented by a letter, such as “H” (130 mph), “V” (149 mph), or “W” (168 mph). It’s crucial to choose a tire with an appropriate speed rating for your vehicle’s capabilities.

Tire Construction

The tire’s construction type is denoted by a letter. “R” stands for radial construction, which is the most common type. Radial tires are known for their stability, comfort, and grip.

Manufacturing Date

The tire’s manufacturing date is represented by a four-digit code towards the end of the sidewall. The first two digits indicate the week of manufacture, while the last two represent the year. For example, “2318” would mean the tire was manufactured in the 23rd week of 2018.

Treadwear, Traction, and Temperature Ratings

Tires also feature ratings for treadwear, traction, and temperature resistance. The treadwear rating indicates the tire’s expected lifespan compared to a reference tire, with higher numbers indicating longer life. Traction and temperature ratings assess the tire’s grip and heat resistance, respectively.

DOT Number

The Department of Transportation (DOT) number is an alphanumeric code indicating that the tire meets federal safety standards. This code also provides information about the tire’s manufacturer and the specific plant where it was produced.


The numbers on my tires might seem like a complex array of information, but they hold the key to understanding your tire’s capabilities, specifications, and safety limits. By deciphering these numbers, you can make informed decisions about tire replacements, ensure proper vehicle performance, and enhance your driving experience. 

Remember to consult your vehicle’s manual and a tire professional to ensure you’re choosing the right tires for your specific needs. Moreover, these details are important when choosing the tire pressure monitoring systems for your vehicle. These TPMS sensors play a crucial role in tire maintenance.

Stay tuned to the Porcsi TPMS blog to find out more tips about improving tire’s life and performance