When interpreting tire sizes, what does the last number in the sequence (e.g., 17 in 225/50 R 17) refer to?

The last number in the tire size sequence, such as the 17 in 225/50 R 17, indicates the diameter of the wheel in inches that the tire is designed to fit. This measurement is crucial because it ensures that the tire will properly mate with the corresponding wheel, allowing it to be mounted securely and function as intended on the vehicle.

In this case, a 17-inch diameter means that the tire is compatible with a wheel that is 17 inches across, which affects the overall handling, ride quality, and safety of the vehicle. Understanding this aspect is essential for anyone involved in maintaining or purchasing tires, as using a tire with an incorrect diameter can lead to improper fitment and significant driving issues.

The other components of the tire code, such as width and aspect ratio, provide additional details about the tire’s dimensions and characteristics but do not directly relate to wheel compatibility.