Automobile Tyres

Published on Jan 19, 2016


In radials tyres the ply or ply cords are alligned at 90 degrees to the circumference. While radials improve performance the fact is that they are not very good for bad roads and overloading. The suspension of a vehicle has, also, to be modified to accept radials. Radials offer much better grip of the road especially on surfaces which offer poor wheel traction like wet of slippery roads.


Treads perform a variety of functions which includes increasing road grip, cooling the tyre while running at high speeds, forming an effect whereby tyres with deeper treads may not pick up loose pebbles and nails on the road, and providing a safe margin of rubber before the complete tyre wear out. In wet conditions they provide ducts through which the water is squeezed out. This in turn helps the tyre grip better. The single greatest cause of tyre damage is improper inflation, which result in unnecessary stress on them and also poor fuel average.

Ensure that tyre pressure is always correct. At least once in every two weeks the tyre pressure should be checked and also when they are cold. Hot tyres will reflect wrong pressures and these will reduce once the tyre gets cold. Make sure the spare is always pressed up correctly, too.Rotate tyres regularly, as per the owner’s manual. Remember that some tyres are designed only for uni-directional mriss-cross.


The best way to safeguard your tyres and give them a long life is by using your right foot carefully. Hard braking or sudden jerky racing starts finishes a tyre faster. Spinning the wheel is another disaster for tyres. Refrain from turning the front wheel while the vehicle is stationery. This also causes excessive wear.

Regular visual inspection is a must, both from inside and outside. Look for cracks, bulges, cuts and odd wear and tear. If you find uneven wear and tear, it may because of bad alignment. This can reduce tyre life drastically, as it causes irregular tyre wear. Avoid overloading of your vehicle. Never exceed the road limit of your vehicle.

Ordinary tyres will have rating like 5.65-12 (as in the Maruti 800). This means the actual cross section on the tyre (in inches) when mounted on the rim (5.65) and normal rim diameter in inches (12). You may also see other number which signify month and year of production, serial or batch number of production line and ply ratings, which simply implies stronger carrying strength.

Radial tyres are marked with numerals, for e.g. 145/70 R 13 T. This means that the 145 (MM) stands for tyre width, the ‘R’ stands for Radial. 70 (MM) is a profile on the sidewall of the tyre. This is the diameter of the wheel with the tyre minus the diameter of the rim. 13 (inch) is the diameter of the rim. The last alpha(T) signifies the permissible speed or performance rating of a particular tyre.

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