At first glance the lettering on the side of the tyre may look complicated. It is not meant to be that way. The lettering explains the exact specification of the tyre you have. In short it tells you anything that you may need to know about your tyre.
From the diagram above we will try to break down what the codes and numbers really mean. The codes on the above tyre, will be different on every tyre, due to a few main factors; the tyre width, tyre profile, tyre size and the speed rating.
The number 165 relates to the Tyre Width
It is the width of the tyre in millimetres.
The number 65 relates to the Tyre Profile
It is the height of the tyre sidewall as a percentage of the width. This is also known as the aspect ratio.
The Letter R relates to Radial Contruction
The number 14 relates to the Tyre's Size
It is the diameter of the tyre's inner rim in inches
The number 79 relates to the Tyre's Load Rating
This is the Load Capacity of the Tyre
The Letter T relates to the Tyre's Speed Rating Value
This indicates the maximum speed for the actual tyre at full load
The E4 Mark
This is to display that the tyre has been tested as high quality by the European Regulatory Authories.