Tyres wearing is normal as they get used so regularly, the tread gradually becomes shallower and the overall tyre performance changes. Wear on your tyres are normal, but there are a variety of reasons that could be causing more wear on your tyres than needed.
It is very common for vehicles to fail a Warrant of Fitness due to wearing on the edge of tyres. Regularly checking the tread depth and condition of your tyres will allow you to know when to replace your tyres but can also help detect other needed repairs. This will help you get the most value out of your tyres and prolong their lifespan.
NZ Tread Tyre Depth 
The New Zealand requirements for minimum legal tread depth is 1.5mm, within all principal grooves that contain these moulded tread depth indicators. The 1.5mm must run the whole circumference of the tyre.
Causes of tyre wearing on the edge
There are many variables of what is causing tyre wear, it comes down to the type of vehicle, the different drivers and their driving habits, and not all tyres are the same.
For example: sports cars with high-performance tyres will wear more quickly than touring tyres on a family sedan vehicle.
1. Incorrect tyre pressure
If your tyre has the incorrect tyre pressure, it will start to wear more quickly and unevenly. When vehicle manufacturers specify the correct tyre pressure it isn’t only to optismise performance, fuel economy, and handling, but to minimize the wear on the tyres. Correct inflation helps with the distribution of vehicle load, acceleration, braking, and cornering.
If the tyre is overinflated or underinflated the contact patch of the tyre tread is not optimized to handle the variety of jobs it is required to do. This will result in wear on the edge of the tyre and uneven wearing.
2. In need of a tyre alignment 
A tyre alignment (wheel alignment) adjusts the vehicle’s steering and suspension components, the system that connects and controls your motion of the wheels. A wheel alignment adjusts the angles of the tyres and their contact with the road. If your tyres are not properly aligned, your tyres will wear unevenly and prematurely.
Incorrect tyre alignment conditions
- Heel/ toe tyre wear: when one side of tread is wearing faster than the other side. It is often caused by the excessive positive or negative toe.
- Feather edge tyre wear: tyres become feathered when the tread is worn lower on one side and higher on the other. This is caused by incorrect wheel alignment and excessive toe and caster.
- One-sided shoulder tyre wear: this type of tread wear means the outside or inside shoulder rib of the tread is more worn than other ribs. This is also known as camber wear and is caused by excessive positive or negative camber.
3. Damaged suspension
If suspension components such as the tie rods become damaged, they can cause tyres to wear more quickly.
4. Car leaning to one side
Damage to the suspension can result in the car leaning to one side. This will apply an increased load to the tyres on one side, causing them to wear quickly on the edge of the tyre.
5. Braking problems 
In some cases, a fault in your braking system can lead to the tyres wearing quickly.
Tyre wear matters
Tyres with little or no tread can create unsafe driving conditions. If your tyres can’t grip the road, you may lose control of the vehicle as the handling is more difficult. In wet and snowy terrain it is even more important you have the correct tyre tread so that the tyres can cut through and make contact with the road surface.
For your own safety and other drivers’ safety, it is best to look after the condition of your tyre tread. It will also extend the lifespan of your tyres and make for overall better vehicle health.
Tyre Wearing and New Tyres in Hamilton
If the low tread on your tyres combined with wearing on the tyre edge or has failed a Warrant of Fitness due to edge wear or tread depth, then come to Grimmer Motors. At Grimmer Motors we will be able to assist you with a wheel alignment or to fit and balance new tyres as needed.