Tyre Information

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.

We recommend a weekly walk around the car to check the tread, look for bulges or wear and to check tyre pressures everytime you fill the tank.

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.

Is your tyre safe?

Because it’s the only part of the vehicle that grips the road, the depth of tread on your tyres is a very important for the safety of your vehicle. It also signals the health of the tyre. Driving with low tread depth increases the potential for tyre failure and aquaplaning. Low tread depth in winter weather conditions can severely reduce grip and control. Motorists driving with tyres under the legal limit also risk a fine.

The first step in checking tyre tread depth is to get good access to your tyres.

- Park on a wide, flat and even surface in a safe place off the public highway with the engine switched off and put the keys in your pocket.
- Put on the handbrake (parking brake) and engage first gear (for manual gearboxes) or park (for automatics).
- Once you have clear and safe access to the tyres you can begin the inspection.
With the tyre tread you can begin to check the depth of the tread and the condition of tyre. Don’t rely on guesswork: purchase an easy-to-use tread depth gauge so that you can monitor your tyres. Measuring tread depth is not difficult with this simple device and requires only a few minutes of time.

The legal minimum tread depth in Europe is 1.6 mm across the central three-quarters of the tread width and round its entire circumference. Check the depth of the main tread grooves in several places across and around the tyre, using the gauge as instructed by its manufacturer. Tyres also have tread wear indicators moulded into the base of the main grooves. When the tread surface is worn to the same level as these indicators, the tyre is at the legal limit and should be replaced.

However you check your tyre tread depths, if they are approaching the legal limit or if you have any doubts, get them checked professionally by a tyre specialist.

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