Eli5: how come tires use marking from different measurement system. Metric for the width, imperial for radius and percentage for height? (like 205/50 R16)

Question

Eli5: how come tires use marking from different measurement system. Metric for the width, imperial for radius and percentage for height? (like 205/50 R16)

In: 422

Answer 1

First number is width in mm. Percentage is highth width ratio. And in metric system if you say something in inches. Then you know it is circle diameter. In most of industry.