TL;DR:
You need new tyres when the tread is below 1.6mm on any part of the tyre. If the tread has worn down to the small raised bars inside the grooves, the tyre is past its safe limit and needs to be replaced. Uneven wear, cracks, bulges, cuts, or vibration while driving are also clear signs you’re due for new tyres.
What causes tyres to wear out over time?
Tyres are constantly dealing with heat, rough roads, potholes, sharp debris and long hours on the bitumen. Even when they still look fine, the rubber can wear down in ways that affect grip, braking and overall safety. Do you need to replace your tyres after a set amount of time? Not always. It depends on how often you drive, the road surfaces you use, your driving style and the conditions your tyres face. In hot regions like Queensland, long stretches of extreme temperatures during summer can also speed up tyre wear.
Below is a simple guide to help you recognise when it’s time to fit new tyres.
Signs you need new tyres
1. Your tyre tread depth is below 1.6mm
The most reliable way to know if tyres are worn out is to check the tread depth.
There is always a raised section in the tread groove that is 1.5mm high, so if your tyre has worn down to that, then it is overdue. If the tread is level with those bars at any point across the tyre, it’s no longer safe.
It doesn’t matter if the rest of the tyre looks alright; if they are below that level, they are under the minimum legal tread depth, which means it’s unroadworthy and needs to be replaced.
Driving on worn tread reduces grip in wet weather, increases braking distance and raises the risk of sliding on slippery roads. It can also lead to fines, and your insurer may deny a claim if the tyres weren’t roadworthy.
2. One edge is worn smooth
If the inside or outside edge has worn flat while the rest of the tread still has depth, you still need new tyres.
This often happens when the wheels are out of alignment or when air pressure has been incorrect for a long time. Uneven tyre wear is a sign that they aren’t maintaining full contact with the road. The car may start to pull to one side, feel less stable in corners or wander on straight roads.
Replacing the tyre and checking the alignment at the same time helps avoid the same issue returning.
3. Cracks, cuts, bulges or missing chunks
Rubber breaks down over time, even on cars that aren’t driven much. Sun exposure, heat and day-to-day wear can create barely visible marks at first, but these small cracks along the tyre sidewall are early signs of ageing. As the rubber continues to dry out, those cracks can spread into weak spots. Cuts, a bulge or a small chunk missing from the side are stronger warnings that the tyre’s structure has already been compromised.
A bulge means the internal layers have separated, which can lead to sudden failure at any speed. Regular checks help you spot these issues early, before they turn into something more serious.
4. Vibration or shaking at certain speeds
If you notice vibration or a light shake through the steering wheel or cabin at certain speeds, especially at high speeds, a worn or damaged tyre could be the cause. This kind of vibration often points to issues like flat spots, internal damage, uneven wear or a tyre that’s no longer balanced.
You might notice it more when accelerating, cruising on the highway, turning, or when emergency braking. Even if the tread still looks fine, a tyre with underlying damage won’t run smoothly and can affect how the car handles, so it’s worth having it checked.
5. A sharp object has punctured the tyre
Not every puncture means the tyre is done for. Small nails or screws can often be repaired if the hole is in the tread and the tyre hasn’t been driven flat. Once a tyre is driven on with no air, the internal structure can be damaged, even if the puncture looks minor.
If the puncture is in the shoulder or sidewall, it can’t be repaired safely. In those situations, a replacement is the only option. If you’re unsure, getting the tyre checked early helps prevent a small issue from turning into something more serious.
6. The tyre is old
Tyres age even when the car spends most of its time parked. Rubber hardens as the years go by, and once it starts to stiffen, the tyre won’t grip the road the same way. Most tyres begin to lose performance once they’re around five years old, so even if the tread looks fine, it’s worth having them checked.
If your tyres are older than five years, a quick inspection now and then can help you pick up any early signs of ageing.
7. Don’t forget the spare tyre
Spare tyres often sit untouched for long periods, but they age just like the ones you drive on every day. Heat, cold and moisture in the boot can slowly dry the rubber out, even when the tyre has never hit the road. It’s worth giving your spare a quick check now and then, and if you spot cracks or tread wear, replacing it early helps you avoid trouble when you actually need it.
We can help with new or second-hand tyres
If your tyres are worn, uneven, cracked or damaged, we can help you fit the right replacement. Coleman Tyres & Mechanical offers both new and second-hand tyres, with a wide range of brands to suit different cars and budgets.
Drop in for a quick tyre check or chat with our team today.