Tyres are the only point of contact between the vehicle and the road. You must therefore
be sure to preserve the quality and performance of your tyres. To do so, we recommend that you comply with the following safety and utilisation advice.

These requirements range from what the manufacturer must be responsible for - relevant sidewall markings etc - and what the motorist should be responsible for - correct fitment and condition of tyre, tread depths etc.

It is recommended that tyres are checked on a weekly basis for tread depth, tread condition, inflation pressure, tread/sidewall damage, any signs of irregular wear. If in doubt seek the advice of a trained tyre expert who will be able to determine the suitability of the tyre for further use.

The penalties for having illegal tyres are currently up to a £2500 fine and 3 penalty points PER TYRE!

The following gives an overview of the relevant points.

There are two important Legal Statutes that Relate to Tyres:

1. The Road Vehicles (Construction and Use) Regulations 1986.
   These regulations do not cover only tyre legal requirements but any area related to road usage and traffic. They include areas related to dimensions and manoeuvrability, brakes, wheels, springs, tracks, steering, vision, instruments, fuel, minibuses, power to weight ratio, protective systems, control of emissions, plates, markings, testing and inspection and conditions related to use.
   
2. Motor Vehicle Tyres (Safety) Regulations 1994
   Which cover the requirements relating to the supply of tyres and areas such as E markings, Part Worn tyres and Re-treads.
   

Tyre Pressures Regulation 27 section b states "the tyre is not so inflated as to make it fit for the use to which the motor vehicle or trailer is put", however this statement is fairly ambiguous. As there is no indication of at what point an under or over inflated tyre becomes unfit for the use it is being put to.

Tyre Cuts

A cut in excess of 25mm or 10% of the section width of the tyre , whichever is the greater, measured in any direction on the outside of the tyre and deep enough to reach the ply or cord would deem the tyre illegal.

Ply or Cord Exposure

If there is any cut in the tyre no matter how small which exposes cords, then the tyre is illegal.

Lumps, Tears and Bulges

Regulation 27 section (d) states - " the tyre has any lump, bulge or tear caused by separation or partial failure of its structure ".It is good practice wherever possible when assessing damage that the tyre is removed from the rim and systematically inspected both internally and externally.

Tread Depth

The legal minimum tread depth for cars and light trailers (including caravans) up to 3500 kgs gross vehicle weight and/or 8 seated passenger vehicles including driver is:

A minimum of 1.6mm in a continuous band throughout the central three-quarters of the tread width, throughout the whole of the circumference

Recommendations

Verify tyre pressures (including the spare tyre) monthly, and before any long trip. Correct the tyre pressures if they no longer correspond to the pressures recommended by the vehicle manufacturer. The tyre pressure should be verified cold (tyres not having run for at least 2 hours or having run for less than 2 miles at low speed) or, if hot, add 4 to 5 PSI to the recommended pressure. Inflation using nitrogen does not dispense with the need to frequently verify the tyre pressure.

In case of unusual pressure loss, have the internal and external condition of the tyre checked, as well as the condition of the wheel and valve. Verify tyre wear (replacement is necessary if the legal wear level is reached), and consult with a tyre professional in case of abnormal wear phenomena or difference in wear between two tyres on the same axle. Any visible puncture, cut, or deformation must be carefully examined by a tyre professional.

Do not use a damaged tyre or one that has run flat without consulting a tyre professional. For tyres designed to run flat under certain conditions, respect the operating instructions supplied by the tyre manufacturer. Any abnormal occurrence such as vibration, noise, or pulling, must be checked immediately personally and then by a tyre professional.
Any repair must be performed by a tyre professional. Any tyre showing clear signs of wear or ageing ("cracking or crazing"...) must be examined by a tyre professional, even if it is un-run or little used (example: spare tyre, tyres fitted to trailers, motor homes, or caravans).