Signs You Need New Tyres: Tread Depth, Age & Legal Limits in NSW

Under Transport for NSW regulations, your tyre tread must be at least 1.5mm deep across the entire central three-quarters of the tyre tread width. Driving on tyres below this limit is illegal, unroadworthy, and risks substantial fines and demerit points.

More importantly, wet braking performance deteriorates drastically once tread drops below 3mm. Tread grooves exist to channel surface water away from the contact patch. Shallow grooves cause hydroplaning (aquaplaning), where the tyre floats on water and loses all steering and braking control.

If your tyre tread is wearing unevenly, the tyres are telling you a story about your chassis and alignment:

Wear on Outer or Inner Edge Only: Indicates incorrect camber or toe alignment, often after hitting a pothole or kerb.

Scalloped or Cupped Wear: Dips or scalloped patches along the tread edge are a clear symptom of worn shock absorbers or loose suspension bushes allowing the tyre to bounce uncontrollably.

Even if a tyre has ample remaining tread (for example, on a spare wheel or caravan), rubber naturally oxidises and hardens over time. Exposure to UV sunlight causes dry rot, visible as tiny hairline cracks along the sidewall and tread valleys.

Check the 4-digit DOT date code stamped on the sidewall (e.g., "2421" means manufactured in week 24 of 2021). Tyres over 5 years old should be inspected annually, and tyres over 7–10 years old should be replaced regardless of remaining tread.