Tyres are one of the most important safety components of your vehicle. Worn tyres reduce braking performance, increase stopping distance, and make driving in wet conditions dangerous.
But how do you know when it’s time to replace your tyres in Australia?
In this guide, we explain:
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The legal tyre tread depth in Australia
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How to measure tyre wear correctly
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Signs your tyres need replacing
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Safety recommendations beyond the legal limit
What Is the Legal Tyre Tread Depth in Australia?
For passenger vehicles in Australia, the legal minimum tyre tread depth is 1.5mm.
Under the Australian Light Vehicle Standards Rules (ALVSR), the tread depth is measured in the principal (main) grooves of the tyre.
These grooves are designed to:
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channel water away from the tyre
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maintain grip on wet roads
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reduce the risk of hydroplaning
If the tread depth in the main grooves falls below 1.5mm, the tyre is considered illegal for road use.
Driving with tyres below this limit can lead to:
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fines
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vehicle defect notices
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failed roadworthy inspections
Legal Update on Tyre Tread Depth in Australia
Australian tyre regulations were updated under the Australian Light Vehicle Standards Rules (ALVSR).
Previously, many drivers believed the entire tyre surface needed to maintain a minimum tread depth of 1.5mm.
However, the current standard generally requires measurement only in the principal (main) grooves.
This means:
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Minor or secondary grooves near the edges may wear down
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The tyre can still be legally compliant if the main grooves remain above 1.5mm
There are still some regional differences:
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ACT and Northern Territory have not fully updated their legislation
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Some inspection manuals may still reference older wording
Because enforcement practices may vary, many experts recommend replacing tyres before they reach the legal minimum.
Recommended Tyre Replacement Depth
Although 1.5mm is the legal limit, safety experts recommend replacing tyres earlier.
| Tread Depth | Condition |
|---|---|
| 7–8mm | New tyre |
| 5mm | Normal wear |
| 3mm | Reduced wet grip |
| 2mm | Unsafe in heavy rain |
| 1.5mm | Legal minimum |
Once tread depth drops below 3mm, wet braking distance can increase significantly.
For Australian road conditions — especially during heavy rain — replacing tyres around 3mm tread depth is strongly recommended.
How to Check Tyre Tread Depth
There are several ways to measure tread depth.
1. Tread Wear Indicators
Most tyres include wear bars built into the tread.
When the tyre surface becomes level with these bars, the tread depth is around 1.6mm, meaning the tyre is at the legal limit.
2. Use a Tread Depth Gauge
A tread depth gauge provides the most accurate measurement.
Simply place the gauge into the main groove of the tyre and read the measurement.
3. The 20c Coin Test
In Australia, you can also use a 20 cent coin as a quick guide.
If the tread does not reach the platypus bill on the coin, your tyres may be worn and should be inspected.
Signs You Need to Replace Your Tyres
Besides tread depth, there are other signs your tyres may need replacement.
Uneven Wear
Uneven tread patterns may indicate:
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wheel alignment issues
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incorrect tyre pressure
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suspension problems
Cracks in the Rubber
Tyres naturally degrade over time.
If you notice cracking on the sidewall or tread, the tyre may need replacement even if the tread depth is still acceptable.
Vibrations While Driving
If you feel vibrations at highway speed, it could indicate:
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tyre damage
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internal tyre failure
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balancing issues
A professional tyre inspection is recommended.
Tyres Older Than 5–6 Years
Even if tread depth looks acceptable, tyres older than 5–6 years may lose elasticity and grip.
Most manufacturers recommend replacing tyres within 6–10 years of manufacture.
Why Worn Tyres Are Dangerous in Australia
Australia’s driving conditions can be challenging.
Heavy rain, long highway distances, and hot road surfaces all increase tyre wear.
Worn tyres can cause:
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longer braking distances
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reduced steering control
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higher hydroplaning risk
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increased accident risk
Maintaining healthy tyre tread depth is one of the simplest ways to improve road safety.
Choosing the Right Replacement Tyres
When replacing tyres, it’s important to choose tyres suited to your vehicle and driving conditions.
Consider:
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tyre size and specifications
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driving environment (city vs highway)
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wet weather performance
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load rating and speed rating
You can browse a wide range of options at:
FAQ
What is the legal tyre tread depth in Australia?
The legal minimum tyre tread depth for passenger vehicles in Australia is 1.5mm, measured in the principal grooves of the tyre.
Do all tyre grooves need to be 1.5mm deep?
No. Current regulations generally require measurement only in the principal grooves, not every minor groove across the tyre.
When should tyres actually be replaced?
Although the legal limit is 1.5mm, safety experts recommend replacing tyres when tread depth reaches around 3mm, especially for wet weather driving.
Can you fail a roadworthy inspection for worn tyres?
Yes. If the tread depth in the main grooves is below 1.5mm, the vehicle may fail inspection and be considered unsafe for road use.
Final Thoughts
Checking tyre tread depth regularly is essential for safe driving.
While the legal limit in Australia is 1.5mm, replacing tyres earlier can significantly improve braking performance and wet-weather safety.
If you’re unsure about your tyre condition, a professional inspection is always recommended.