Tire Sizing Explained

When shopping for tires, knowing how to read your tire’s sidewall can be very helpful. The letters and numbers give you information about your tire size, speed rating, load index, and operation purpose.

 

When the letters and numbers are broken down and explained, its actually quite simple to understand them. Let’s go over a popular passenger tire size together:

 

Here's how to break down the following passenger tire size:  P215/60R16 94V

 

The “P” stands for passenger.

 

Other letters you might see are:

 

- LT: Light Truck

 

- ST: Special Trailer

 

- T: Temporary (spare tire)

 

- “215” is the width of the tire from sidewall to sidewall.  The larger the number, the wider the tire.

 

- “60” is the aspect ratio. This is the official sidewall height shown as a percentage of section width.

 

- “R” is the radial construction. This is the industry standard for passenger car and truck tires.

 

- “16” means this tire is designed to fit on a rim with a 16 inch diameter. If you plan on upgrading your wheel size and the wheel diameter changes, you’ll have to purchase a new set of tires that match the new diameter.


- “94” is the tire's load index. It is a measurement of how much weight each tire can support. “94” indicates a maximum weight of 1,477 pounds per tire. Be sure you multiply your load carrying capacity by 4 to get the total capacity for a complete set of tires.

 

This number can vary but each number can be found on the Load Carrying Capacity Per Tire Chart below:

Load Carrying Capacity Chart.jpg

“V” measures the speed rating and signifies the tire can safely drive up to 149 mph for an extended amount of time.

 

The table below shows what each speed-rating letter represents:

Speed Rating Chart.jpg