Tyre Size Guide

Each tyre contains a code and at first glance it may be confusing for motorists. To help you understand what the coding means, we've provided an explanation.

A tyre size is made up of several parts and is considered in millimetres. Th width, the profile (percentage of the width), the diameter of the inner rim, and the load and speed ratings. Below is a typical example for how this is written and what the numbers all mean:

tyre size guide

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's 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 displays what each letter represents:

Codemph
A-J62
K68
L75
M81
N87
P94
Q100
R106
S112
T118
U124
H130
V149
ZOver 149
W168
(W)Over 168
Y186
(Y)Over 186

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If you have any further questions about tyre sizes or would like to book a mobile tyre fitting, please get in touch with us on 0800 810 0972