TYRES : How can I tell when my tyres need changing?

One sign that your tyres need changing is noticing a deterioration in performance. For example, your car does not handle or grip the road as well in poor weather conditions as it normally does, or it takes longer to stop when you apply the brakes.

The fact that tyres wear gradually can make it difficult to identify the reduction in performance, so it's best to have them checked regularly and preferably by an expert. It is the driver's responsibility to ensure that the tread on your tyres is not worn beyond the legal minimum limit of 1.6 millimetres.

To make this easier to identify, tyre manufacturers mould tread wear indicators (T.W.I) into the design of the tyres tread pattern usually at a tread level of 1.6mm. As soon as the tread is worn to the height of the tread wear indicator, the tyre has reached the legal minimum tread depth and you should replace the tyre as soon as possible.

You should also be aware that there are many different reasons for tyre wear. Your tyres don't just get worn through age and use, but through emergency braking, under-inflation or over-inflation. And if your wheels are misaligned, one edge of the tyre can wear more rapidly than the other edge.

Illustrations and explanation for tyre wear

	Under Inflation Under-inflation has caused this tyre to wear on the outer edges of the tread, leaving the central tread area far less worn. The tyre inner-liner can also degrade.
	Over Inflation Over-inflation has resulted in the central tread area being forced into contact with the road causing rapid or crown wear.
	Mis-Alignment A typical example of the wear pattern caused by front wheel misalignment, (Toe-in or toe-out). The edge of the tread is "feathered" and worn progressively from one side.
	Camber Wear Excessive wheel camber has caused sloping wear on the outer edge of the tread on one shoulder of this tyre.
	Illegal Wear This tyre has been used well after reaching the legal minimum pattern depth of 1.6mm across the central ¾ of the tread, going around the complete circumference of the tyre.
	End Of Life This tyre has reached the legal minimum pattern depth of 1.6mm.
	Emergency Braking An emergency braking manoeuvre with this tyre has caused the tyre to rapidly wear through the complete casing causing the tyre to deflate.
	Cuts Sharp objects can cause considerable damage rendering a tyre unserviceable.
	Impact Damage This is damage caused by an impact to the sidewall. The bulge or "egg" indicates localised casing damage.