The sidewall of a modern car tyre is a "mine" of useful and necessary information

The sidewall of a modern car tyre is at first sight a confusing mixture of numbers, letters, codes and symbols that means absolutely nothing to the man in the street! And yet cracking the code reveals a whole load of useful, important and necessary information.

The tyre is arguably the most important safety component on a vehicle, only four patches of rubber, each no larger that the palm of a hand, are all that connects the vehicle with the road surface. There are now so many types of tyre available for different applications and with the increase in the purchase of tyres over the internet, when it is necessary to provide correct size and related information – all these vital details are contained on the sidewall.

According to TyreSafe, motorists are woefully ignorant when it comes to the tyres on their cars. A recent poll conducted by the UK's leading tyre safety organisation revealed that a staggering 80% of motorists did not know the legal minimum tread depth and a large percentage have no idea what the symbols on a tyre sidewall denote - many do not know which size of tyre they need in the event of a replacement.

TyreSafe has produced a leaflet entitled Car Tyres and Your Safety. Here are the details to crack the code:

1- Brand or trade name of the tyre - i.e. Continental, Dunlop, Goodyear, Michelin, Pirelli etc.

2 - Tyre model or pattern code. For example Sport, Pilot, Eagle etc

3 - Tyre size - The width of the tread expressed in millimetres, which in this illustration is 205; the aspect ratio – height of the tyre sidewall as a percentage of the width, in this case it is 55% of 205mm; and the diameter of the tyre's centre hole, expressed in inches.

4 - Service description - in this example the figure 91 denotes the maximum weight capacity of the tyre according to the official load index table, which translates to 615 Kg, The letter V indicates the speed rating of the tyre, in this case the tyre suitable for cars capable of reaching a maximum vehicle speed of 149.1 mph.

5 - ECE (Economic Commission for Europe) Regulation 30 Conformity Approval Number – which means that the tyre meets the standards of the European Regulatory Authorities.

6 - EEC Noise Approval Number, which means that the noise generated by the tyre is within approved European limits.

7 - Date of manufacture. This is important as the age of a tyre can affect its performance. The first 2 numbers refer to the month and the 3rd and 4th numbers refer to the year

8 - Denotes tubeless construction

9 - Safety warning refers to the dangers of under-inflation/overloading and the mounting of tyres together with the risk of severe over - inflation.

10 - Direction of rotation which relates to directional tyres only. These tyres are designed to rotate in one direction only .

11 - Outer/inner sidewall refers to the mounting of asymmetric tyres only.