Your car tyres are the only thing connecting your vehicle to the road while driving. Therefore, they are paramount to your and your passenger’s safety. The last thing you want is to be driving around with unroadworthy tyres.

In this article, we’ll show you how to ensure your tyres keep you safe by learning to measure tread depth with just a 20c coin! You’ll also find out what an acceptable tyre tread depth is, why it’s so essential for safety and much more!

Tyre tread depth – what is it?

Tyre tread refers to the rubber on the circumference of a tyre that makes contact with the road. As tyres are used, and kilometres are racked up on them when driving, the tyre’s tread is worn off. When the tyre tread wears, the tyres grip the road less effectively. A worn tyre can be very dangerous, especially in the wet! When tyres have minimal tread, their ability to dispel water lowers. This means an older tyre with less tread will take longer to stop when driving in wet conditions.

Quite simply, the less tyre tread depth, the less effective the tyre will be at providing traction to the road. Just a few millimetres may not seem like much, but when your tyre tread is worn down to the minimum, there is a massive difference in the wet weather grip of your tyres. 

When you purchase a new set of tyres for a standard passenger car, they usually come with a tread depth between 8 and 9mm – just under a centimetre. Obviously, this will change depending on the type of vehicle – for example, they’ll be much more tread depth on the tyres you’ll find on 4WD, dual-cab utes and trucks, for example.

The ideal and minimum tyre tread depth

You might be asking what is the legally allowable minimum tyre tread depth in Australia? 1.6mm is the minimum tyre tread depth in Australia, which means that if your tyre tread is less than 1.6mm, your car is considered unroadworthy and unsafe.

Depending on what state of Australia you live in, driving with tyres below the legal tyre tread depth means you risk a hefty fine, a loss of demerit points or both.

Despite this, most tyre manufacturers recommend changing tyres when the tyre tread depth is 3mm or less. Anything less than this amount will start to affect your tyres’ all-around performance, particularly braking and cornering.

The tyre tread test – using a coin!

Although the legal limit for a tyre’s tread depth might be 1.6mm, most places will recommend changing your tyres when they have 3mm of the tread or less left.

Every tyre will have a tread wear indicator built-in; the indicator is located between the ridges of the tread of the tyre. If this still confuses you, then there’s a straightforward way to check your tread depth; all you need is a 20c or 10c coin!

Testing tyre tread with a 20c coin

Push a 20c coin into your tyre tread vertically, and if the tread doesn’t reach the platypus bill printed on the coin, then you have less than 3mm tread depth remaining!

Tested tyre tread with a 10c coin

Push a 10c coin into your tyre tread vertically, and if the tread doesn’t cover the outside band printed on the coin, then you have less than 3mm tread depth remaining!

To ensure the safety of yourself and others on the road at all times, make sure you regularly check your tyre tread. Still not sure? Let the experts at Sutherland Automotive do a full inspection. Book an appointment today!