Rim size refers to the diameter of the wheel's outer edge, typically measured in inches. It is an important specification for vehicles, as it affects tire compatibility, handling, and overall performance. A larger rim size can enhance the appearance of a vehicle and improve cornering stability, but it may also lead to a harsher ride. When selecting tires, it's crucial to match them with the correct rim size. Each tire is designed to fit a specific rim diameter, ensuring proper contact with the road. Using the wrong rim size can lead to safety issues and decreased performance of the vehicle, including braking and fuel efficiency.