Tyre Size – What you should know
Each tyre contains a coding and at a first glance it may look quite confusing. To help you understand what the coding means Event Tyres have produced the following summary.
The tyre size is made up of several parts, the width of the tyre in millimetres, the profile (percentage of the width), the diameter of the inner rim and the load & speed ratings. So in this example;
225/45 17R 91Y
The width (A) is 225mm
The profile is 45% (B = 101mm)
The diameter (C) is 17 the R stands for Radial. If there is no letter then it is a cross ply tyre.
The 91 is the load rating and the Y is the speed rating
Tyre Speed rating
The speed rating is the maximum speed for the tyre. The table below shows you what each letter represents.