Tyres are the only contact your car have with the ground. This article intends to give you the basic knowledge of tyres and tips for maintaining tyres in top notch condition.
Functions of a Tyre
- It forms the contact between the car and the road.
- It supports the car: the air inside the tyre supports the car.
- It absorbs the road shocks when cars run on the road.
Basic parts of a tyre
- Tread: The thick layer of rubber that comes in contact with the road. Tread have patterns cut to squeeze away water from the path to maintain grip.
- Shoulder: Connects the tread and the side wall.
- Side wall: Part connecting Shoulder and bead, the side wall should be neither very rigid nor very flexible. The relevant information about the tyre is written on the sidewall.
- Bead: The bead comes in contact with the wheel (rim) and attaches tyre onto the rim.
- Carcass: The basic skeleton comprising of an inner layer of cord fibre.
- Belt: A cord layer between the carcass and the tread to protect the carcass.
- Inner Liner: A layer inside rubber lining which resists air diffusion and replaces the inner tube in the tyre.
Type of Tyres
There are different types of tyres based on the climate, driving requirements and terrain. Find below various type of tyres:
- All Season tyres: Tyres which can be used in all weather conditions like dry, wet, cool or hot. These tyres are mostly offered by manufacturers in their new cars. They have adequate grip, good tyre life and decent cornering grip. They can be best named as the Jack of all trades tyres.
- Performance/ Summer tyres: These tyres are mostly found in performance cars and give outstanding grip in high-speed dry conditions. They are made of soft components.
- Winter tyres: These are tyres that perform well in snow. There are two types of snow tires: studded and stud less. Studded tyres have tiny studs to grip on the snow and prevent cars from sliding on the ice.
- Off-road/ All Terrain tyres: These tyres are used in SUVs tackling hostile off-road conditions. The components are not too soft or hard. They have stronger side walls. They are not very comfortable on normal roads as they make a lot of tyre noise and also wear out quickly.
- Run Flat tyres: These tyres have the capability to hold the shape, withstand the weight of the car and can run for some 70-90 Kilometers without air. Such tyres are used to save space for the spare tyre and also you can run to reach the nearest service/ tyre shop with the run-flat tyre in the event of a puncture.
Markings on Tyre
Have you ever wondered the markings on the sidewall of a tyre? The side wall of a tyre has all the details about the tyre.
- Tyre Size: You would have noticed number like 185/65/R15, 225/60/R15, 235/70/R16 etc. Let us help you to decode it. For description purpose, let us choose 225/60/R15
- 225: Indicates the tyre width in mm
- 60: It is the aspect ratio or the height of the side wall. Here it is 60% of tire width i.e. 60% of tire width of 225 mm that is 135 mm is the side wall height.
- R15: R indicates it’s a radial tyre. 15 indicates the diameter of the rim in inches on which the tyre can be fitted, here the tyre fits an15 inch rim
- Speed Rating: This is represented by an alphabet, which indicates the maximum speed for which the tyre can be used. Following are the speed ratings:
Speed Rating Kilometers/Hour N 140 P 150 Q 160 R 170 S 180 T 190 U 200 H 210 V 240 Z 240+ W 270 Y 300
3. Load Index: The number indicates the maximum weight an individual tyre can withstand. This number is located after the Tyre size and before the speed rating.
|Load index||Load in Kg per tyre||Load index||Load in Kg per tyre||Load index||Load in Kg per tyre||Load index||Load in Kg per tyre||Load index||Load in Kg per tyre|
- Date of Manufacturing: There will be an 11-digit serial number, of which the last four digit of the code indicates the date of manufacturing, for example, if the code of a tyre is 700311513214, the last four digits indicates that the tyre is manufactured on the 32nd week of the year 2014. The manufacturing date of tyres is crucial in ascertaining the kilometers run by a car. If the odometer reads at 15000 KS and the car have a tyre which is after the registration date of the car, ask the owner the reason for this variation.
Tips for Tyre maintenance
- Maintain correct air pressure: Always maintain correct air pressure in all wheels. Under inflation and over inflation of tires are equally bad. Under inflation reduces efficiency by increasing rolling resistance, decreases tread life, bends the tyres, affects steering precision and cornering stability. Over inflation makes the ride harsher and causes increase uneven tyre wear.
- Wheel Alignment and Balancing to be done regularly: Wheel alignment prevents the car from pulling to one side and uneven and fast tyre wear. The wheel balancing ensures the weight is distributed evenly on the tyre circumference. This prevents vibrations, especially during high speeds.
- Tyre Rotation: Tyre rotation is done to ensure even tread wear on all tyres and prolong the service life of tyres. This can be carried out simultaneously during the scheduled wheel alignment and balancing.
- When to Change Tyres: Regularly inspect tyres for uneven tread wear, bulges, and side wall cracks. Replace a normal tyre when the tread is worn out below the recommended tread depth levels, this can be ascertained by the tread level indicator. Check the tyre by expert after five years. Don’t use any tyre above 10 years even if there is tread left on the tyre.