Here's why you should increase size of tyres, carefully

What’s in a tyre and why should owners give a lot of importance to it?

It’s normal for people to think of a tyre as one of the least important parts of the car. It is the opposite really. Being the only part that is in contact with the surface, the car’s performance partly depends on the tyres. It may not matter much if it is a small car. But if it is a sedan for example, there is little point in having a powerful engine and good handling, but poor tyres.

Naturally, a car will not be fitted with bad tyres in the factory. But at the manufacturer level, there is a tendency to keep the cost of the car down by not fitting performance tyres.

The easiest improvement you can make is replacing factory-fitted tyres with better tyres of the same size. The better tyres will offer better driving comfort, there will be less noise and they will last longer if maintained properly.

Using low profile tyres is a good option. Low profile tyres have smaller sidewall (the surface which you see, the one that is not in contact with the road). Similar to changing from steel rims to alloys, the visual appeal of the car will go up instantly.

Low profile tyres will also improve cornering performance. The tradeoff will be lower ride quality. This may not be advisable in India as bad roads are common.

Upsizing is fitting bigger diameter or wider tyres to the car. Doing this has benefits. Wider tyres will offer more grip because there is more contact between the tyre and road. Upsizing also offers better cornering and braking performance.

An important point to note is that if the tyre size is increased, low profile tyres should be bought to compensate for the bigger diameter. If a lower profile tyre is not used, there is danger of the tyre hitting the wheel arch. This is asking for serious trouble.

There are a few disadvantages in increasing tyre size. The first is lower fuel economy because more grip with wider tyres increases rolling resistance. Bigger or wider tyres also make the steering feel heavier.

Upsizing car tyres could be an expensive affair too. If the car is used only for city driving, it may not be worth the extra cost.

The general rule is that the tyre size increase should be in the range of two to three percent. Changing tyre size should also be done at a good store and with professional advice.

The speedometer may have to be recalibrated if the tyre size is changed. This is because a tyre with a bigger diameter will travel more. With low profile tyres, it will travel less.

Filling the tyres with pure nitrogen is considered better for the tyres. Nitrogen is said to migrate through tyre rubber less. This means less fluctuation in tyre pressure and longer life.

Changing to bigger or wider tyres can be a rewarding experience if done professionally. Otherwise, it can prove to be disastrous when it comes to the ride quality of the car.

Some manufacturers do not honour car warranty claims if the tyres have been changed while it is still valid.