Keeping Tyres Legal
In the UK the legal minimum tread depth is
1.6mm over 75% of the tyre width. The law also requires that vehicles
are fitted with the correct type and size of tyre for the vehicle type
and purpose of use.
If your tyres do not meet these requirements you are liable for up to 3
penalty points and up to £2500 fine per tyre.
When should tyres be changed?
Under performance is one sign, for example, poor handling in bad weather
or increased stopping time when you brake.
So that you can identify when your tyre needs changing, tyre
manufacturers mould tread wear indicators (TWI) into the design of the
tyre - usually at 1.6mm.
You should change your tyre before they reach this indicator to stay
legal.
What causes tread to wear?
There are many different causes of tread wear in addition to wear
and tear.
Emergency braking, under/over inflation and misalignment are also major
causes of tread wear.
What tyres are fitted to your vehicle?
Tyre sizes are made up of a series of numbers and letters;
for example - 205/45 R 17 84V
1) "205" - In the example above - this is the width across the tyre in
millimetres.
2) "45" - In the example above - this is the height of the tyre side in
millimetres.
3) "R" - In the example above means Radial construction.
4) "17" - In the example above is the diameter of the inner rim in
inches.
5) "84" - In the example above is the load capacity index.
A look up chart is required. In this case 84 = 500kg
6) "V" - In the example above is the speed rating of the tyre.
In this case V= 149.1mph
