What does R20 in tires mean?

[BradyFitz]

Tire R20 refers to the diameter of the wheel rim being 20 inches. Here is some extended information: 1. Wheel rim size: The size of the wheel rim generally refers to the diameter of the wheel rim. The larger the wheel rim size, the higher the aspect ratio of the tire, and the better the handling stability of the car. However, the larger the contact area between the tire and the ground, the greater the resistance when the car is moving, and the more fuel it consumes. To ensure driving safety, each type of tire must use an appropriate wheel rim. 2. Wheel rim offset: The wheel rim also has other parameter values, such as the wheel rim offset, which is the ET value. The wheel rim offset refers to the distance from the centerline of the wheel rim to the mounting surface. The smaller the offset, the more the wheel rim will protrude out of the car after installation. When replacing a new wheel rim, it is also important to note that if the offset of the new wheel rim is larger than that of the original wheel rim, or if the width is too large, there may be friction with the vehicle's suspension system.