Car Tyres

A tyre is used to provide a cushion between the vehicle and the road , to reduce the transmission of road shocks and also to provide the necessary friction for it to move.However the role of tyres in a car's performance it not limited to this, it also influences the Fuel Efficiency, Steering Resistance, Braking, ride comfort and the overall performance of the car.

Tyres Types based on construction :

Car tyres are divided into two categories based on the mode of their construction.

• Radial tyres
• Cross-ply or Bias tyres.

Radial and Cross -ply (bias) tyres

Radial tyres

Radial tyres are the preferred choice for modern day cars, patented by Michelin in 1946.The backbone of the tyre usually consists of  plies of cord or steel. The steel is placed circumferencially as a belt .Over the belt are the plies of reinforcing tyre cords that extend from bead to beadat angle of 90 degrees to the centreline of the tyre hence the name Radial.

Why do we use Radial tyres...?

The reasons for using Radial tyres are extensive,however it boils down to the following ...

• Its square shaped footprint which is preferred for its even pressure distribution and less soil penetration.
• Exhibiting superior Traction and good Stability.
• Even wear
• High Mileage
• High durability
• Resistance to punctures.

Cross-ply or bias tyres :

The main design aspect of bias tyres is its crisscross pattern of  cord design. The cords that reinforce the tyre extend diagonally across the tyre from bead to bead (bead here refers to the bead bundle that properly seals and seats the tyre onto the rim of the wheel.) an angle of 30 to 40 degrees to the centreline of the tyre. As a result of such patterning a successive layering of cords are obtained which run in opposite directions.

Are Cross-ply tyres the best choice..?

Cross -ply tyres have a very simplistic design and hence are very easy to repair. However they have a round footprint and an uneven pressure distribution and hence Radial tyres are preferred over them.

Which tyres do you have in your car..?

Well if you have a car from the production lines of 2000 or later it is mostly probable that you have radial tyres on your car.

Tube and Tubeless tires :

Tube tyres are those which include a tube to seal the air inside the tyre .Whereas tubeless tyres have continuous ribs molded integrally into the bead of the tyre so that they are forced by the pressure of the air inside the tyre to seal with the flanges of the rim of wheel.

Tread Designs : 

The treads of a tyre are the portions of the tyre which actually make contact with the road.The treads provide traction to the wheel for the car to move. Based on tread designs tyres can be categorized as :

• Directional: Directional tread patterns are used in tyres which are to rotate in a given direction designated by an arrow pointer in the side.
• Non-Directional :These are the tyres which can rotate in any direction i.e, can be put on any wheel.
• Symmetric : These have symmetric tread patterns for stable handling and traction.
• Asymmetric : These have special designs which are not symmetric and have use in specified driving conditions .

How long do the Treads last..?

 The tread wear can be ascertained by the wear indicators on the tyres. Check for the elevated rubber portions in the grooves of the tyre-if they are at the same depths with the adjacent tread ribs then it is time to change your tyre .

Unequal wearing of the treads may be caused by improper alignment of the wheels , incorrect placement of the suspensions and improper tyre inflation. This may lead to bad handling , bad braking and also a bad fuel economy .

Run Flat tyres :

As the name suggests Run flat tyres are the tyres which enable the driver to continue with the journey in case of a puncture within specified speed and distance regulations before the tyre need to be changed .Thus RFT s have a major safety benefit .The RFT technology is a reinforced sidewall that keeps the tyre beads firmly seated to the wheel rim enabling the wheels to support to car's weight in case of a flat.

What are Winter tyres and Summer tyres..?

Based on the climatic situations of a country the tyre technology also changes to adapt to the surroundings.In countries that experience a lot of snowfall , the all season tyres and the summer tyres are of no good.Using the all season tyres would certainly put the safety of the driver and the passengers in jeopardy .

Winter tyres are have specially designed rubber that remain soft even at a very low temperature and complex tread designs that help it to grip to snowy surfaces better.

Some other information about tyres :

• Speed rating : Speed rated tyres mean that the company that manufactures the tyres have specified that that tyre model is suitable for running at such and such speed ,designated by letters like S,H,V & Z on the tyre sides.

(S-upto 180 kmph, H-upto 210kmph, V-upto 240kmph, Z- 240 kmph+)

• Load index : The load index of a tyre tells us how much load the tyre is designed to support according to the manufacturer's guidebook .The load index chart gives us the necessary details.

• Car Specification : Tyres are specified by the manufacturer for consumer use by Letters like P,LT,C,T etc.

(P-Passanger car,LT-Light Truck,C-Commercial Vehicle,T-Temporary tyre.)

• Radius of tyre : The tyre radius can be obtained from the markings like R-14 on the tyre sides.
• Section width of the tyre : The section width of the tyres can be ascertained from the markings on the sides of the tyres by the three digit numbers eg-240 , which denotes that the section width of the tyre is 240 mm. 

Are tyres really of this much importance ...?

Yes,they are....a Car with the right set of tyres for the road is much safer and a far better performer than a car with bad tyres.So go get the correct ones....

Happy Driving...!!!