Tyres are an extremely important part of the car, and they are also the most neglected. We often take the lifespan of tyres for granted, refusing to change them unless they are punctured.

But in reality, these have their own specific lifespan and need to be replaced as well. There are some fundamental aspects about tyres that need to be understood, for us to determine when they need to be changed.

The first and most important of these aspects is tread depth.

What is tread/tread depth?

Tread depth can be defined as the vertical distance between the top section and the base of its deepest groove. The tread depth of each tyre, measured in terms of /32 of an inch, depends upon the type of vehicle it is attached to.

In general, the tread depth on an average varies between 10/32 inch or 11/32 inch.

Why is tread depth important?

When you come to think about it, tread should actually decelerate a car and reduce its efficiency by creating an increased amount of friction between the road and the tyre.

Since the roads are bumpy and uneven, tread depth is necessary to maintain the balance of the vehicle even on wet roads. By dispersing water from the contact patch (the part of the tyre which stays in contact with the road when it rotates), the tread actually enables the tyre to grip the road better.

Obviously, without proper tread depth, it would be easy for the car to skid off the road, especially in bad weather conditions or on slippery streets. In short, safe driving requires proper tread depth.

So, when is my tyre officially worn out?

Legally, when the tread depth reduces to about 2/32 of an inch, it needs to be replaced. That is the legal limit. However, the recommendations of your manufacturer may differ.

Here are the symptoms which will let you know that you need to get your tyres replaced:

• When the tread depth has worn down beyond the recommended levels
• When the sidewall of the tyre is damaged
• When you spot a hole in the tread depth exceeding 6mm
• When the edge of the tyre that sits on the wheel (the bead) is either damaged or has been removed.

All these symptoms indicate that your tyre needs to be replaced.

However, if you spot certain symptoms, but are not very sure whether you should opt for a replacement or simple repairs, we suggest that you consult a professional for help.

Can I stop my tyre from wearing out?

Yes, only if you never use your car. Even then, your tyres will need to be replaced. There are certain forms of defects that come with age, and they simply cannot be avoided.

It is imperative for you to get the tread depth checked at least once every five years. If they are still good to go, you will be able to continue using the tyre.

However, if the tread depth has been worn down below the recommended levels, it will need to be changed for your own safety.

Also, any tyre that has exceeded the ten-year mark must be changed immediately.

What about spares? Do they need replacement too?

The process of ageing holds true for spare tyres as well. Normally we don’t give a second thought to the spares, mainly because they don’t come into use very often, but it is important to keep your back-up up to date as well.

Spare ones that are more than six years old should only be used in extreme situations. For example, if you acquire a puncture in the middle of a highway, you can use your six-year-old spare tyre.

The ten-year rule holds true for spares as well. If you have a spare tyre that has been sitting in your trunk for ten years, you should replace it immediately even if you have never used it.

How can I slow down the ageing of my tyres?

Although the replacement process is inevitable, there are certain steps you can take to keep your tyres from burning out too soon:

• Make sure that your tyres are always set to the correct inflation pressure. Too much or too little pressure can wear your tyre out unevenly, thus leading to even more damage.
• Rotation is an effective way of using them to their full potential. Normally the tyres wear out differently depending upon their position on the car. If you keep changing the location of each tyre, each one of them can wear out consistently.
• Do not spin or lock the wheels while accelerating or braking, since it causes further damage.

Conclusion

It is important for you to inspect your tyres regularly to ensure that they are in good shape. Also, you should be aware of the details of the inspection to avoid getting duped by mechanics. Look for all the symptoms mentioned above, and lay special attention to the tread depth measurement, before deciding to change the tyre.