Most drivers judge their tyres by tread depth alone. Plenty of tread? She'll be right. But rubber is an organic material, and it deteriorates over time whether you drive on it or not. A tyre can look perfectly healthy on the outside while the rubber underneath has hardened, cracked and lost the grip it had when new. If your car does low kilometres — think a second car, a caravan, a ute that mostly sits in the shed — age can catch up with your tyres long before the tread wears down.
How to find your tyre's date of manufacture
Every tyre sold in Australia carries a date code moulded into the sidewall. Look for the letters DOT followed by a string of characters — the last four digits are the ones you want. The first two digits are the week of manufacture and the last two are the year. So a tyre stamped 2321 was made in the 23rd week of 2021.
You may need to check both sides of the tyre, as the full code sometimes appears on only one sidewall. If you can only find a three-digit code, the tyre was made before the year 2000 — and it should have been replaced a very long time ago.
How long do tyres actually last?
There's no single legal expiry date for tyres in Australia, but most manufacturers and motoring bodies suggest a practical lifespan of around five to six years from the date of manufacture, with ten years as the absolute outer limit regardless of how good the tread looks. From about the five-year mark, it's worth having tyres inspected annually by someone who knows what to look for.
How quickly a tyre ages depends on how it lives. Rubber breaks down faster with:
- UV exposure — cars parked outdoors in the Australian sun age their tyres faster than garaged cars
- Heat — hot bitumen and hot climates accelerate the chemical breakdown of rubber compounds
- Underinflation — running low pressures builds extra heat inside the tyre casing
- Sitting still — tyres on parked vehicles develop flat spots and crack sooner, because driving actually helps distribute the protective waxes in the rubber
Signs a tyre is past it
Age-related deterioration usually shows up before a failure. Take a close look at each tyre — including the spare — for:
- Cracking or crazing in the sidewall or between the tread blocks, often looking like fine spiderweb lines
- A hard, shiny or faded surface where the rubber has lost its suppleness
- Bulges or distortion in the sidewall, which can signal the internal structure is letting go
- Vibration that wasn't there before, sometimes caused by flat spots or internal damage
Any of these is a good reason to have the tyre professionally inspected, even if the tread depth is well above the legal minimum of 1.5 mm.
Don't forget the spare
The spare is the most commonly forgotten tyre on the car. It ages in the boot just as surely as the others age on the road — often faster, since it rarely gets the benefit of regular flexing. There's little worse than pulling out the spare on the side of the highway and finding it cracked or flat. Check its pressure and condition every few months, and check its date code next time you're looking at the others.
A five-minute habit worth having
Once or twice a year, walk around your car and give each tyre a proper look: date code, sidewall condition, tread wear and pressure. It takes five minutes and it's one of the cheapest pieces of insurance going — your tyres are the only part of the car that actually touches the road.
If you're not sure how old your tyres are or whether that sidewall cracking is anything to worry about, the team at Global Tyres Geelong in North Geelong can take a look and give you an honest answer — and if a tyre does need replacing, they'll sort you out with the right fit for your car and budget.