How to Check Tyre Tread & What's the Legal Depth in Australia?


Oct 05th, 2021

How to Check Tyre Tread & What's the Legal Depth in Australia?

Everyone's probably seen at least one funny video of people driving around with entirely bald tyres on their car. Sure, those videos are entertaining and quite amusing, but worn-out tyres with shallow tyre treads are no laughing matter!

In Australia, the minimum tyre tread depth for all vehicles is 1.5 mm. Depending on what Aussie state you’re in, tyres with shallower treads will get you fined or demerited. Other than penalties, shallow treads will reduce your car’s traction and increase the dangers you face. The solution? Get your tyres replaced, ideally when the tyre treads pass below 3 mm in depth.

The depth of your tyre tread is a serious matter, so keep on reading as we dive into everything you need to know about it!

What Is the Legal Tyre Tread Depth in Australia?

In Australia, the legal tyre tread depth is 1.5 mm. 

First, you should understand that the depth of your tyres’ tread isn’t just a nice-to-have type of thing. Your tyres are the part of your car that meets the road, hence critical to safety, so much so that there’s a legal tread depth that you must comply with.

The Australian legal minimum requirement for tyre tread depth (1.5 mm as mentioned above) is pretty much the same as everywhere else. Most countries around the world set their legal requirement at around 1.5 mm or 1.6 mm. 

Regardless of that legal minimum, tyre manufacturers, mechanics, and other automotive specialists will agree that it’s best to replace your tyres before the treads get close to that level.

Brand new tyres typically have a tread depth of 7-9 mm, and most manufacturers recommend replacing your tyres by the time they get to 3 mm.

What Happens If Tyre Tread Depth Doesn’t Meet Legal Requirements?

As you might already know, states and territories in Australia are independent of each other when it comes to managing their roads. What’s common to all is that there are consequences for having tyres that don't meet the legal tread depth.

The punishments will differ depending on where you’re based. Still, you can expect fines or even demerits if you’re caught with tyres that make your vehicle unroadworthy.

3 Ways to Measure Tyre Tread Depth

You’re probably wondering how to check tyre tread depth for your car to ensure that you’re complying with local laws. The three most common methods are:

1. Tyre Wear Indicator

Tyres have a built-in wear indicator that you can use to visually inspect the tread’s depth. These are little blocks within the tread that measure up to the legal minimum of 1.5 mm. 

So, when you see that the treads are at the same level as those blocks, it’s telling you that the tread depth equals 1.5 mm, the bare minimum depth.

Sure, this is a neat little built-in feature, but the blocks aren't so helpful. Why so? You’ll only notice them once you've reached the minimum requirement, not before.

2. Tyre Tread Depth Indicator Tool

Another helpful approach is to buy a little tread depth indicator tool. It’s inexpensive and small, and it will show you precisely how deep your treads are so you can monitor them from time to time. That’ll help you prepare to buy a replacement long before you reach the legal minimum requirement.

3. Coin Tread Test

Another nifty approach, if you can’t or don’t want to buy any tools, is to use a 10-cent or 20-cent Aussie coin. With the 10-cent coin, just slide it into the tyre tread. If the outside band of the coin is hidden, then the tread is still alright.

With a 20-cent coin, check if you can’t see the platypus’ bill when you slide the coin in the tread. If you can't, that's good. It means you’ve got at least 3 mm of tyre tread depth remaining.

Why Does Tyre Tread Depth Matter?

Indeed, why does any of this matter? Sure, you’ll want to follow the rules to avoid the fines and demerits, but there are reasons more important than that to make sure your tyre treads are still deep.

Here are some of the top reasons why tyre tread depth matters.

Tyre Tread Depth = Grip on The Road

First and foremost, let’s remember why those tyre treads exist in the first place. They exist to provide your tyres with plenty of grip on the road underneath.

Again, your tyres are the contact points between your car and the road underneath. The treads on your tyres ensure that those contacts with the road are as strong as they can be to maximize your handling and prevent slipping and sliding.

Maintain Traction

When your tyres become too worn out and the treads get shallow, your car loses traction (i.e., the grip it has on the road). Less traction means that your car's overall handling and performance will become affected.

Extended Braking Times

The matter of extended braking times is so critical that it’s worth mentioning as a separate point. Shallow tyre treads mean less traction, and that translates to extended braking times

Simply put, your car will take a longer time than usual to come to a halt when you slam on the brakes.

That can potentially be terrible news if you’re trying to stop your car from hitting another vehicle, or even worse, a pedestrian.

Prevent Hydroplaning or Aquaplaning

Last but certainly not least, a car with shallow tyre treads runs the risk of hydroplaning, also known as aquaplaning. That’s what happens when your car slides uncontrollably when driving on water or ice.

What to Do When Your Tyre Treads Are No Longer Deep Enough

Alright, so we know what the minimum tyre tread depth is and why it matters so much. Now, what can you do if your tyre treads are running a little too shallow? Well, the only real solution is for you to replace your tyres.

Since this is directly related to your vehicle's safety and a substantial fine is involved, you should not delay doing this.

Please refer to our complete guide on how and when to get your tyres replaced, including the approximate costs involved. 

Find a Tyre Dealer Near You

Tyre treads getting too shallow? Well, why not locate the closest tyre dealer to you right now! You can do that by checking out the Directory over at Select ‘Tyre Suppliers & Workshops’ from the dropdown menu and key in your location to find the nearest tyre specialists now!

By Ray Hasbollah