Sidewall Markings
Tyre sidewall markings help vehicle users to identify, purchase and correctly maintain their tyres. Initially they were only used to help identify the tyre's make. Over the years, Government legislation has demanded safety markings be posted in order to help buyers know they are getting a legal tyre.
Markings now fall into two main groups:
- Those essential markings which tyre manufacturers have long used to indicate make, size and type (including recommended inflation pressure and direction of rotation)
- Markings which have been added over the years in order to respect the requirements of legislation in the principal areas where UK tyres are used: UK, USA, Australia and Europe
To access the sidewall marking explanations, click on the letters within the blue circles.
Manufacturer's name or brand name
A commercial name or identity in some form (i.e. SP10 or SP SPORT 9000)
The tyre size designation
The word 'radial' to identify radial ply tyres. R in size marking also indicates radial ply tyres
The word 'tubeless' to identify tubeless tyres (or 'tube type' (optional) where appropriate)
Various additional legal markings, some of which have no relevance to UK, or European operations are also shown.
Legislation requiring tyres fitted as replacements to carry an 'E' type approval number became effective 1st January 1985.
Legislation requiring all passenger cars and their trailers to be fitted with new tyres to 'E' or 'e' type approved became effective on the 1st January 1995.
All car tyres sold from 1st July 1997 must carry an 'E' marking. The 'E' or 'e' mark consists of an 'E' or 'e' followed by a number included in a circle of 12mm diameter or a rectangle. This symbol is followed by a further number
The 'E' certifies that the tyre complies with the dimensional, performance and marking requirements of ECE Regulation 30.
The 'e' certifies that the tyre complies with the dimensional, performance and marking requirements of DIRECTIVE 92/23/EEC.
The number associated with the letter 'E' in the circle or 'e' in the rectangle is the code number of the government which granted the type approval (No. 11 for the British Government and a different identifying number for each of the other European countries involved).
The number outside the circle or rectangle is the number of the type approval certificate issued for that particular tyre size/type.
Service description - the 'service description' combines two pieces of information known as the 'Load Capacity Index' and the 'Speed Category Symbol', for example '79V'
It always appears adjacent to the tyre size marking. These characteristics are defined in the European and UK legislation and in the tyre industry standards in accordance with the tables headed as follows:
- 'Load Capacity Index' indicating the maximum load carrying capacity of the tyre (see table)
- 'Speed Category Symbols' indicating the maximum speed of the vehicle to which the tyre may be fitted (see table)
TWI - is the abbreviation of 'Tread Wear Indicator' and may be found in the shoulder or upper sidewall part of some tyres
This marking is placed on the tyre to indicate where the tread wear indicators are located across the tread pattern. When these special markers in the tread pattern become flush with the remainder of the tread, it indicates the tyre is or is about to become illegal, because of lack of tread depth.
Directional pattern tyres
Tyres with directional or asymmetric patterns should always be fitted such that they rotate in the correct direction as indicated by an arrow marked on the tyre sidewall. Failure to observe this is classified as a reason for refusal to issue an MOT test certificate.
If a directional tyre has to be fitted so that it rotates in the wrong directional (e.g. temporary use of a spare tyre following a puncture), then without undue delay the vehicle should be taken to a tyre dealer or garage so that a correct tyre can be fitted.
DOT - is the abbreviation of (U.S.) 'Department of Transportation'
DM DF O5Y XXX (A U.S. Federal Code)
A statement of 'maximum load' and 'maximum pressure' as required by U.S. Federal Government
Not applicable in the UK.
A group of markings required by U.S. Federal Government, identifying the cord materials used in the tyre construction and the number of plies
The majority of modern UK manufactured car tyres may carry this information since some may be used in the U.S.A.
Country of origin - most tyres are marked with the name of the country or national geographical area where they were manufactured
Uniform tyre quality grading - U.S. Federal Government requirement
Safety warning - for the consumers information
Serious injury may result from:
Tyre failure due to under inflation/overloading. Follow owner's manual or tyre placard on vehicle. Explosion of tyre/rim assembly due to improper mounting. Only specially trained persons should mount tyres.
Other markings of importance that may appear on the sidewall where applicable are:
Reinforced: a marking which is added adjacent to the tyre size marking to indicate that the tyre has a higher load carrying capacity than the standard tyre. The principal application of 'reinforced' type tyres is on vans and light trucks but they are also fitted to certain estate cars and caravans.
M and S: mud and snow - a marking to identify tyres with a winter tread pattern. In the case of 'V' or 'Z' tyres with no service description, the maximum load permitted at the maximum speed of the vehicle must be shown on the sidewall.
Hot or Not
Amphibious Pod Vehicles
What is it?
Do you know your RS4 from your elbow? Or your killswitch from a hole in the ground?
Sign up
Call yourself a driving enthusiast? Then watch this space as we are about to launch the Dunlop Drivers Club and will be giving you the chance to be part of it here - Coming soon!
