What's Legal (and What's Not): Victoria's Minimum Tyre Tread Depth Rules

Driving on tyres that are below the legal tread depth isn't just a safety issue. In Victoria, it's also a compliance issue that can affect your registration, your roadworthy certificate, and in the event of an accident, potentially your insurance claim. Here's what the actual rule is and how to check it yourself in under a minute.

The legal minimum in Victoria

Under Victorian road rules, tyres must have a minimum tread depth of 1.5mm across the tyre, measured in the principal grooves around the entire circumference, not just at one point. That means a tyre that measures fine in one spot but has worn down to below 1.5mm anywhere across its width or circumference is still considered non-compliant.

The 20-cent coin trick

You don't need a professional gauge to get a rough read on tread depth at home. Insert a 20 cent coin into the tyre's main tread groove with the platypus's bill pointing down into the tread. If the tread covers the bill entirely, you're comfortably above the legal minimum. If you can see the whole bill, or most of it, it's time to get the tyre properly measured and very likely replaced.

Why uneven wear catches people out

The trickiest part of this rule is that tyres rarely wear perfectly evenly. A tyre can look fine across most of its width while being dangerously low on one edge, often the result of an alignment issue, as covered in our alignment articles. This means a quick glance at the middle of the tread isn't enough; a proper check needs to look across the full width and at multiple points around the tyre.

What happens if you don't meet the standard

Driving on tyres below the legal tread depth can result in a fine and demerit points if you're pulled over, and it will fail a roadworthy inspection outright if you're renewing registration or selling the car. Beyond the legal side, tread depth is directly tied to your car's ability to grip the road and disperse water in wet conditions. Most of the tyre's wet weather performance is lost in the last couple of millimetres of tread, well before you reach the legal minimum.

If you're not sure where your tyres currently sit, it's a quick, free check at any TYREPLUS HTR store. 

Come and visit us today or call us on  (03) 9560 0442  and we'll measure tread depth properly across the tyre so you know exactly where you stand before your next rego renewal or roadworthy check.