While it’s easy to forget, checking the condition of your vehicle’s tyres is essential, as poor tyre conditions can be hazardous.
The easiest ways to check your tyre tread are to use the in-built indicator, the 20c coin trick, a visual inspection of the sidewalls, or a tyre depth indicator gauge. However, many people choose to have a mechanic inspect it for a professional appraisal of their tyres.
Throughout this blog, you will learn how to check tyre wear and tyre tread depth, as well as learn what causes tyre wear and how to care for your vehicle and prevent excessive tyre wear where possible between professional car inspection appointments.
Read on to learn everything you need to know about tyre inspections.
What Are the Signs You Need New Tyres?
Several signs indicate it may be time to invest in a new set of tyres. It is important to remember that not all of these indicators will occur simultaneously. Even a few minor signs alone should be regarded as important.
Signs of tyre wear to look out for include:
- Bulges or Blisters – The most obvious signs that your tyres require an urgent replacement include cracks in the tyre sidewall, excessive vibrations whilst driving, and bulges or blisters on the tyre.
- Cracks in the Tyre Sidewall – A crack in the sidewall of a tyre is typically due to the ageing process. Over time, as tyres age, the rubber loses flexibility and begins to harden. Superficial cracks start to form, and whilst usually not too problematic at first, the longer you drive on them, the more serious the damage will become. Tyres with multiple large cracks are more at risk of a blowout, which can be extremely dangerous.
- Excessive Vibrations While Driving – Whilst there are many factors involved that could be causing excessive vibrations when driving, tyre problems are usually the main culprit. Wheel alignments can sometimes fix the problem, but first we suggest checking the inflation in your tyres. Over-inflated tyres can cause the tyre to take on more of a rounded base shape, reducing the amount of tyre-to-road contact.
- Inadequate Inflation – Under-inflated tyres are also an issue, as the tyre is more at risk of wearing unevenly on the outside edges. An under-inflated tyre also forces your vehicle to work harder against the tyre resistance when rolling, ultimately leading to an overheated tyre. More often than not, the tyre body will separate from the tyre tread, causing a blowout.
- Depth of the Tyre Tread – Additional signs of poor tyres that may be less obvious include the depth of your tyre tread and air leaks. It is essential to check your tyre tread at least fortnightly to ensure you have an adequate tread thickness and are not at risk of driving on bald tyres.
How to Check the Wear on Your Tyres
There are a number of ways to check the wear and remaining tread on your tyres. The following are some of the most favoured and frequently used methods.
Most of us have spare change in the car. To check the tyre tread depth using a 20c coin, place the coin’s edge in between the grooves of the tyre tread, ensuring the number 20 on the coin is upright furthest away from the tyre. If the tyre tread does not meet or go above the platypus bill, you will likely only have 3mm or less of tyre tread remaining. If your tyres appear to have 3mm or less, you need to arrange a new set of tyres stat!
In-Built Tread Wear Indicator
Tyres have in-built tread wear indicators on the outside wall of the tyre, and in between the grooves of the tyre tread. The outside indicators are often arrows or small lines depending on the tyre brand, the four indicators are spaced equally around the tyre, and you will notice that when the tyre tread wears down, it begins to align with these indicators. When this occurs, you will need to arrange for the tyres to be replaced, as their tread life is almost complete.
The indicators between the tread grooves are usually raised notches, and the same rule applies to those. When the tyre tread wears down and begins to align with these indicators, you will need to arrange for the tyres to be replaced.
Tyre Depth Indicator Gauge
The most accurate way to check your tyre tread and know whether it is time to arrange a new set of tyres is by purchasing a Tyre Tread Gauge. These can be bought from most trade and automotive supply stores. This is a very simple tool and fits in your pocket or car bag easily.
You can check your own tyres with these great little gadgets in three easy steps.
Pull out the measuring probe until it is fully extended, place the end into the base of the tread groove and push down, allowing it to retract naturally until the outer of the probe presses against the top of the tyre tread. Repeat this for each tyre.
Hot Tip – When measuring, measure around the whole tyre circumference to check that all sides of the tread are wearing evenly.
You will also want to ensure that when you are measuring, you are placing the gauge against the base of the groove and not on a raised indicator notch.
Checking the Condition of the Sidewall
It is important to check all tyre sidewalls regularly. We may not notice the extensive elements our tyres are exposed to daily. Jagged potholes, rocks, sticks, gutters, and other miscellaneous items can damage your tyre immediately or over time.
We recommend doing a thorough tyre check every 2-3 weeks. It helps to maintain clean tyres as dirt and mud build-up can hide possible issues. It is straightforward to check the sidewall of each tyre by completing a thorough visual inspection as well as running your hands along the rubber to feel for any noticeable imperfections, bulges, or cracks.
If you are not confident in checking your tyre tread, many mechanics will happily do it free of charge if you pop down to their workshop. Some mechanics will quickly check by sight or touch, and others may offer you a fancier option if you book an appointment, like electronic tyre wear tester machinery.
What Causes Tyre Wear?
Tyre wear can be caused by many factors, either alone or together. Six of the main factors include:
- Worn Suspension – Worn suspension puts a lot of pressure on the tyres, leading to accelerated and uneven wear.
- Damage and Impact from Driving – Our tyres are constantly exposed to sticks, rocks, potholes, and uneven roads, causing damage to their surfaces over time.
- Incorrect Air Pressure – Incorrect air pressure, whether over- or underinflated, can cause the car to put too much pressure on the tyre in one spot, leading to over-worn sections of the tyre or a potentially bursting tyre.
- Uneven Wheel Alignment – An uneven wheel alignment means that the load share between the tyres is uneven, causing one or more tyres to bear more than their recommended load. This causes uneven tyre wear and the potential for one tyre to give way unexpectedly.
- Natural Wear Over Time – Natural wear over time is caused by regular driving and exposing the tyres to the natural road surface and elements.
- Excessive and Heavy Braking – Excessive or heavy braking can cause tyre sections to wear down quickly. This can off-balance the tyre itself and cause pressure, leading to bubbles or weak spots on its surface.
How Often Should You Check Tyre Wear?
Tyre wear should be checked every 2 to 3 weeks unless you have been on unusually rough terrain or you believe you hit a bump or pothole at an excessive speed. In this case, you should check the tyre within 24 to 48 hours of this occurring.
Because tyre damage can occur either quickly or slowly over time, it is best to check frequently to catch potential issues before they cause a hazard while driving.
Is It Time to Get My Tires Replaced?
If you believe your tyres are showing some or all of the warning signs we mentioned throughout this article, it may be time for you to look into a new set of tyres. We always recommend you consult your locally trusted mechanic if you are still unsure. As with anything, your safety is the ultimate priority!
For Bundaberg residents and locals, Shift Automotive prides itself on our quality and honest services for each customer. We are more than happy to extend our services to you if you want a second opinion on the current state of your tyre tread.
To make the most of your time with us, we would like to offer an electronic brake testing service that also includes electronic tyre wear checking.
How Does Uneven Tyre Wear Occur?
Many factors can contribute to uneven tyre wear. Some of these include misaligned tyres, over- and underinflated tyres, worn suspension, excessive heavy braking, and damage or impact from driving.
What Is the Legal Tyre Tread Depth?
Whilst new tyres generally have around 7-9mm of tread to begin with, the Australian standard of legal tyre tread depth is a minimum of 1.5mm. It has been proven that the length of time it takes for a vehicle to come to a stop lengthens significantly after the tread depth reaches 3mm or below.
What Are the Tyre Safety Standards in Australia?
Australian automotive vehicles and the parts that make up the vehicle itself are regulated by the ADR (Australian Design Rules). The vehicles and their components must meet very strict and important safety standards.
By law, all vehicles will have a label or information sticker clearly stating the requirements for the tyres. These include recommended air inflation pressure, tyre size, speed ratings, endurance strength, etc. Manufacturers have held these requirements since circa 1970.
Along with an interior label or information sticker, each tyre is required to provide the same information and the date of manufacture.
This article is published in good faith and for general informational purposes only. Shift Automotive does not make any warranties about the ongoing completeness and reliability of this information, and specifics will vary according to your vehicle’s manufacturer and model. This article is not intended to replace consultation with a qualified automotive service technician.