How to measure tyre tread depth?
Measuring tyre tread depth for all Australians is a really easy vehicle maintenance task that every car owner should know about.
When you have new tyres fitted to your vehicle, they will have around 8 to 9 mm of tyre tread depth and will gradually wear down over time. When they reach a minimum your wet weather grip will be severely impacted, making your car much more likely to skid.
Why does tyre depth matter?
It’s a safety issue
As the tread of your vehicle tyres wears down, their ability to disperse water reduces. Consequently, in wet conditions, older tyres can increase the time it takes for your car to come to a stop, and potentially cause an accident.
Legally you are required to replace your tyres when your tread depth wears below 1.6 mm, however, at Kumho, we recommend maintaining a tread depth of at least 3 mm to avoid a reduction in tyre capability.
Legal requirements
In some states of Australia like NSW, you require a vehicle inspection on any vehicle more than five years old to renew your registration. The vehicle inspection includes a check by an authorised mechanic of your tyres. If the tread is less than 1.6 mm, you will be advised to replace the worn tyres before the inspection certificate is issued.
Even in states, like Victoria and Queensland that don’t have a vehicle inspection requirement it is still illegal to drive with tyres that have less than 1.5 mm in tread depth.
How do you measure tyre tread depth?
There’s a couple of ways to check the tread depth of your tyres.
1) Check the tyre tread wear indicator
The simplest method of checking tyre tread depth is via the built-in indicators. Every Kumho tyre contains small blocks that sit within the tyre tread. Once the tyre tread reaches 1.5 mm, the tyre tread wear indicator will appear level with the tyre indicating it has reached its minimum depth.
2) Purchase a tyre tread depth indicator
If you want to more precise then visit your local auto parts stores and buy a tyre tread depth indicator. It is a simple tool for calculating the exact measurement of the tyre tread depth.
3) Use a coin or something similar
Using a 10 or 20 cent coin, find a mark on the coin that is around 1. 5 mm. Place the coin in the tyre tread groove. If the part of the coin that you’ve determined to be at the 1.5 mm mark is still obscured by the groove, then it’s still legal. You can also use the same method for measuring 3 mm if you’re planning to take our advice and replace your tyres at this point.
What else do I need to know about tyre wear?
If your car tyres are worn unevenly but not necessarily worn out, it is usually a sign of a steering or suspension problem. You should have your tyres checked by an authorised repairer and ask them to rectify the problem. It will make your car safer and maximise the life of your tyres.
What if I’m unsure?
If you are unsure about measuring the tread or want to have your tyres checked by a professional, visit a Kumho authorised dealer. Visit the Kumho website to locate your nearest dealer and for other tips about maintaining your tyres.