Key questions on tyres

During this period, I have noticed that motorists who ask me questions about automobiles can’t tell the difference between the manufacturer’s suggestions in the owner’s manual that can be followed or overlooked without causing any danger, and what the manufacturer prohibits due to risk of danger to the motorists and others.

Most don’t know the importance of the tool box and what it does. The lack of attention like this has led to many accidents before.

An important tool that is usually forgotten or misunderstood is the tyre. A large number of motorists want to know how much pressure should be filled into their tyres. They want to know the exact pressure, although the tyre pressure depends on personal preference and type of use, and there is a safe range of pressures a set of tyres can be inflated.

Under-inflated tyres will cause the vehicle to consume more fuel while acceleration will also be slower than vehicles wearing properly inflated or over-inflated tires, although the ride quality is better. Under-inflating the tyres will cause the tyre to wear out unevenly.

You will notice a black stripe in the centre of the tyre tread, which is the part of the tyre that did not touch the road as the left and right rims of the tyres take up all the weight. Apart from more wear on the sides, under-inflated tyres also tend to explode more easily than properly-inflated tyres, especially when travelling long distance or at high speeds.

For over-inflated tyres, the black stripe will be on the sides, not in the middle, as they are unable to touch the road. If they are used in this condition, the middle part of the tyre will start to wear out more than the rest. So, if you start seeing uneven wearing out on the tyres, make sure you have the right pressure pumped in.

Uneven tyre wear can also point to suspension malfunction, for example if the tyre tread shows uneven or wavy wear pattern, then one of the shock absorbers is not functioning properly. Have them checked and replaced if needed.

However, if the wavy wear is on the rims of the tyres, check whether the wheel bearings are loose or worn out. This is a sign that the ball bearing is not working properly, or the wheel may not be rotating smoothly. If there is a wheel spacer, remove the wheel and check whether the spacer is still nice and tight. However, if the strip appears only on one side, take the vehicle to have the wheels aligned in order to prevent further tyre damage.

As for the pros and cons of filling the tyres with nitrogen, this is a very popular question during the last five years. First, you must understand that nitrogen is used in order to stabilise the air temperature in the tyre when driving long distances and at high speeds. Using nitrogen would lower chances of tyre explosion in this respect. But nitrogen that is filled into the tyres have a high level of normal air in it, thus the effects will also be less.

Another advantage of using nitrogen is that there is a lower chance of water droplets forming inside the tyre, due to the smaller temperature difference when the tyre is cold and hot. The water drops are one reason that vibration could be felt up the steering, just like a vehicle that has not gone through wheel alignment.

The deciding factor of using nitrogen seems to be the cost. Usually it is free when you fill the tyres at the fuel station, but nitrogen will cost you Bt200 (Bt5 per tyre). I wouldn’t consider filling the tyres with nitrogen to be a waste.