the tread depth of your tyre regularly. The lower the depth, greater the
braking distance on wet roads. 'Aquaplaning' may occur even
at low speeds with tyres which have inadequate tread depth. Tyres must
be replaced when the tread has worn down, exposing the tread wear indicator
mark. These marks stand 1.6mm above the base of the tread grooves. An
easy way to check this depth is by inserting a One Rupee coin in the grooves
- if the 'matra' of the Hindi word 'Rupiah' is visible, then it's time
for you to spend rupees for a tyre change.
Remember, tyre age is a result of physical and chemical processes and
impair its performance. This applies to all tyres that are used little
or not at all. So even if your tread depth appears deep but if it's over
five years old, change them.
Finally, never fit tyres whose history is unknown to you - this is especially
important in case of second-hand or cheap tyres. At the prevailing times
of recession, you might come across variable cost difference from different
retailers, but if such differences are huge between retailers for the
same tyre it's would be worth your while to investigate.