How to Read Tire Size Manchester NH


It’s obvious that the tires on your car are extremely important, as without them, you won’t be able to drive anywhere in Amherst, Manchester, or Derry.

There may be a point when you’ll need a new set of tires. If that’s the case, you’ll want to know how to read tire size, so that you can get the right ones for your vehicle. Learn all about tire size below, and schedule your tire service at Ira Toyota of Manchester today.

Reading the Tire Sidewall


You’ll find tire size on the sidewall of a tire. The sidewall has different letters and numbers that represent different aspects of the tire. To explain it in more detail, we’ll use the example P215/65R15…

  • Tire type:The letter P tells you that the tire is used for passenger vehicles. You may also see the letters LT, which means that the tire is used for light trucks.
  • Tire width:This is represented by 215, and is measured in millimeters. So, in this case, the tire is 215 millimeters wide.
  • Aspect ratio:The two numbers after the slash describe the aspect ratio. This is the ratio of the height of the tire’s cross-section to its width. In this example, the tire’s height is equal to 65% of the tire’s width. And the bigger the aspect ratio, the bigger the sidewall will be.
  • Construction:The letter R stands for Radial. This means that the tire was designed to have layers running radially across it.
  • Wheel diameter:The last two numbers signify the size of the wheel measured from one end to the other. It basically tells you the size of the wheel that the tire is intended to fit. Here, the tire is made for a wheel with a 15-inch diameter.

Other Important Numbers/Letters


There are usually some numbers and letters that are located on the sidewall after the tire size. For instance, you may see 98H. The 98 represents the load index. This tells you how much weight the tire can support when it’s properly inflated. This number ranges between 75 and 105 for passenger tires, with each value representing a specific carrying capacity.

The H is a speed rating, and is shown by different letters of the alphabet. Each letter corresponds with a maximum speed that the tire can withstand under the recommended load capacity. In this example, H means that the vehicle has a maximum speed of 130 MPH.

Furthermore, the tire has a DOT Serial Number that recognizes the tire manufacturer’s compliance with the U.S. Department of Transportation (DOT) tire safety standards. This 4-digit number is located on the inside sidewall, near the rim. It tells you when the tire was made, by the week and year. For example, if you see 1209, then the tire was made in the 12th week of the year 2009.

Contact Us for More Information

If you need more information about tire size, or need new tires near Amherst, Manchester, or Derry, then contact us at Ira Toyota of Manchester. Our service technicians are knowledgeable in all things tires, so they can answer any auto inquiry that you may have.

We look forward to hearing from you!