On the sidewall of a tyre you will find
various codes and markings. The list below aims to simplify the
coding system and allow you, the user, to understand the valuable
information imprinted on the sidewall.
Tyre Sizes
Tyre sizes are made up of a number of different numbers and letters.
For example tyre size 175/70 R 13 82 T is made
up of the following information:
175
The tyre section width in
millimetres
70
The aspect ratio in % (the
height of the sidewall divided by the tyre's width)
R
Denotes the tyre's construction
type - in this case it's a radial
13
Rim diameter in inches
82
Load Index
T
Speed Rating
Tyre Age - Tyres
carry a three digit age code on the sidewall indicating the month
and year of manufacture. For example 129 means the tyre was manufactured
in December 1999.
Other Markings
M&S - Identifies Mud and Snow tyres
DOT Codes - Coding satisfying the requirements
of the US Department of Transportation contain a mixture of letters
and numbers such as DOT DVDE MTA 129
E-Marks - Tyres for sale in the European Community
must carry an E -Mark in accordance with ECE Reg 30 - E.g. E4 027550
