Checking the tread depth of your tyres is simple and easy – and all you need is a 20c coin. To measure your tyre's tread depth, place an Australian 20c coin into one of the central circumferential grooves of your tyre. If the tread doesn't reach the bill of the platypus, your tyre has less than 3mm of tread remaining.
Check the tread indicators
Small bars of rubber running across the grooves in between the tread – called tread wear indicators – tell you when the tyre is worn out. If the tread is worn down to these bars on any part of the tyre, it's worn out, unroadworthy, and needs to be replaced.
The Treads App captures your drives and miles automatically and notifies you when it is time to schedule to rotate or replace your tires – all from your phone.
→ Driving with an outward bulge is always unsafe and may result in a tyre blowout. If your tyre has such a bulge, replace it immediately! → Similarly, large cracks and deep bruises also call for a tyre change. They may allow air pressure leakage, which will only increase with time.
Generally, we advise that tyres should last around 40,000km, but that's not a guarantee. So much of a tyre's lifespan depends upon factors that are either within the control of the driver or within no one's control at all. That's why tyre manufacturers never make guarantees around longevity.
Checking the tread depth of your tyres is simple and easy – and all you need is a 20c coin. To measure your tyre's tread depth, place an Australian 20c coin into one of the central circumferential grooves of your tyre. If the tread doesn't reach the bill of the platypus, your tyre has less than 3mm of tread remaining.
Generally speaking, the tyre replacement frequency is 5-6 years. Tread depth - With time, a tyre tread will wear down. Check the tread depth regularly and make sure they are within legal limits.
Changing tyres in pairs
But should tyres be replaced in pairs? The answer is ideally, yes. Replacing just the one tyre without changing the tyre on the opposite side of the axle at the same time may cause an imbalance to the vehicle – potentially leading to wheel misalignment and excessive tyre wear.
All tyres (including spare tyres) more than ten years old should be removed from service and replaced with new tyres.
There must be no damage to the tyre body - sidewalls or tread, no bulges or cuts. The energy lost when a tyre is moving is known as 'rolling resistance'.
As a general rule, the National Highway Traffic Safety Administration (NHTSA) recommends that drivers change the tires on their vehicles every six years. However, there are several factors that can place additional wear and tear on tires that force drivers to change them more frequently.
A tyre sidewall is not always perfectly even; sometimes there will be dimples and indentations. Indentations are harmless and aren't detrimental to either driving or safety characteristics. The dimples are superficial. You're looking for bulges and splits.
Tires can become damaged for a variety of reasons, and it can happen without the driver being immediately aware there's a problem. The most common types of damage are punctures, cuts, impacts, cracks, bulges and irregular wear.
Bulges, bubbles, cuts and tears in the sidewalls are all signs that the tyre needs further inspection by a professional – and the likely diagnosis will be that a replacement is necessary. Damage can occur through hitting the kerb, stray nails and other sharp metal objects, hitting a particularly bad pothole and so on.
#1 – Causes of Tire Failure: Under-inflation
This problem is compounded when driving at highway speeds during hot weather for long periods of time. When the tire gets excessively hot, the rubber begins to degrade, which if driven on long enough, leads to a rupture in the sidewall of the tire, or tread separation.
Internal damage, sidewall damage, deep cuts, huge gouges, or a split from a burst tyre are not repairable. As a rule of thumb, holes larger than about 5 - 6mm across should not be considered safe for repair.
A lump or bulge usually indicates the tyre has been damaged internally. If you notice a lump, bulge or cut then the tyre will more than likely need to be replaced or repaired immediately. You may also notice cuts, rips and tears to the tyre as a result of 'kerbing' or pot hole damage.
There is no definitive tyre age limit as to when you should replace your tyres but once your tyres reach 7-10 years old, you should keep a close eye on their condition and consider replacing them. Tyre ageing is commonly identified by small cracks, known as crazing, which appear in the tyre sidewall.
The most common reason for tyre wear on the edges is underinflation. If you've noticed wear on the inside, check the outside of the tyre too. Underinflated tyres tend to distort the tread away from the road in the centre, which results in the edges becoming worn.
We recommend replacing tires aged 6-10 years, no matter how much tread remains. When it comes to replacing tires, things can be a little unpredictable. Mileage, condition and routine maintenance all contribute to the tire's safety and usability. You should replace them if you think they may have compromised integrity.
If two of your tires wear out faster, it may only be necessary to replace those two instead of replacing all four. If you do, it's important to have the two new tires installed on the back and the partially worn tires moved to the front – even on front-wheel-drive vehicles.
Because tyres are the only point of contact between your car and the road, having two different tyres on the same axle is not advised. Pairing an old tyre with a new one will cause an imbalance in rolling resistance and grip, causing unpredictable performance, steering problems and using more fuel.