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How Do You Read a Tire Code?

  • Tires
  • Did you know
Tire Code
Tires are one of the most important components of any vehicle. They are responsible for ensuring the safety and performance of the vehicle, which is why it is crucial to choose the right tires for your vehicle. When buying new tires, it is important to understand the tire code, as it contains important information about the tire's size, type, and performance capabilities. In this article, we will discuss what a tire code is, and how to read it.


What is a Tire Code?
A tire code, also known as a tire size code or a tire identification code, is a combination of letters and numbers that indicate important information about the tire. The tire code is typically located on the sidewall of the tire, and it contains information about the tire's size, type, and performance capabilities. The tire code is standardized across all tire manufacturers, making it easy to understand and compare different types of tires.


How to Read a Tire Code:
To understand the tire code, you need to know what each letter and number represents. Here is a breakdown of the most common tire codes and what they mean:


Tire Type:
The first letter in the tire code represents the type of tire. There are two main types of tires:

  • P: Passenger tire - designed for use on passenger cars, SUVs, and light trucks.
  • LT: Light Truck tire - designed for use on heavy-duty trucks and SUVs.


Tire Width:
The next three numbers represent the tire's width in millimeters. This number indicates the distance from one sidewall to the other, measured at the widest point of the tire when it is mounted and inflated to the manufacturer's recommended pressure.


Aspect Ratio:
The next two numbers represent the tire's aspect ratio. This number represents the height of the tire's sidewall as a percentage of the tire's width. For example, if the aspect ratio is 50, the sidewall height is 50% of the tire's width.


Construction:
The next letter represents the tire's construction. There are two types of tire construction:

  • R: Radial construction - the most common type of tire construction, in which the tire's plies run perpendicular to the tire's centerline.
  • D: Bias-ply construction - an older type of tire construction, in which the tire's plies run diagonally across the tire's centerline.


Rim Diameter:
The next two numbers represent the rim diameter in inches. This number indicates the diameter of the wheel that the tire is designed to fit.


Load Index:
The next number represents the tire's load index. This number indicates the maximum load capacity of the tire, based on a standardized scale. The higher the load index, the greater the tire's load capacity.


Speed Rating:
The final letter in the tire code represents the tire's speed rating. This rating indicates the maximum speed that the tire can safely handle. There are 17 different speed ratings, ranging from Q (99 mph) to Y (186 mph).


Example:
To illustrate how to read a tire code, let's take a look at an example:

P225/50R17 94V

  • P: Passenger tire
  • 225: Tire width in millimeters
  • 50: Aspect ratio (50% of the tire's width)
  • R: Radial construction
  • 17: Rim diameter in inches
  • 94: Load index (maximum load capacity of 1,477 pounds)
  • V: Speed rating (maximum speed of 149 mph)

Understanding the tire code is an important part of choosing the right tires for your vehicle. By knowing how to read the tire code, you can make an informed decision when purchasing new tires, based on your specific needs and safety.