Frequently Asked Questions
What is the minimum legal tyre tread depth?
In the UK a tyre must have a minimum of 1.6mm of tread. Most manufacturers include a tyre bar that is visible when the tread is low. However it is recommended that tyres should be replaced when tread get below 2.5mm in depth.
How do I check the size of my tyres?
The tyre size is written on the sidewall of the tyre and specifies the width, profile, wheel size, speed rating and load index.
e.g 185/50R14 82R
185 – This is the nominal section width of the tyre. In this case 185mm.
50 – This is the profile height or aspect ratio. It is a percentage of the tyre width.
R – Indicates the tyre has a radial construction. The is the most common type of tyre fitted in the UK. Other types are Cross ply and Bias belted
14 – This is the diameter of the wheel the tyre fits in inches.
82 – This is the load index and indicates the maximum load the tyre is designed for. Replace tyres with the same or higher value as recommended by the vehicle manufacturer.
S – This is the speed rating. It indicates the maximum speed a tyre can maintain at full load. Replace tyres with the same or higher value as recommended by the vehicle manufacturer. All tyres fitted in the UK are capable of the legal speed limits.
Why is the tyre pressure important?
Under or over inflating a tyre can reduce its effectiveness and shorten it’s life span. Tyres should be inflated to the vehicle manufacturers specification. To test tyre pressures you can use a gauge available from most car accessory shops for a few pounds or use your local garage. Modern pumps will inflate or deflate a tyre to a set pressure.
Under inflating a tyre can lead to a serious reduction in it’s lifespan. When pressure drops to 80% of the correct figure tyre life shortens to 75%. If the pressure drops to 60% the life is reduced to less than 40%. Check your tyres for uneven tyre wear as this can often be an indication of incorrect tyre pressure.
Over inflating can lead to less grip as less of the tyre is in contact with the road surface. This will lead to uneven tyre wear.
Correct tyre pressures also improve fuel efficiency,
Is it safe to use instant tyre repair products?
These products can get you going quickly, but driving on a punctured tyre will almost certainly cause irreparable damage to the tyre.