Do tyres deteriorate with age?

Tyre ageing and deterioration

Tyres naturally deteriorate with age, and this happens to all rubber products, regardless of whether they have been used or are still in storage.

What causes deterioration

• Oxidation - Oxygen reacts with the rubber and causes the rubber to harden and lose its flexibility
• UV exposure - Sunlight breaks down the rubber compound
• Ozone - The atmosphere has some ozone, and when this comes into contact with rubber it causes surface cracking
• Heat - High temperatures increase the rate of the above factors, and the deterioration will happen more quickly

What this means in practice

Old tyres have less grip, are more likely to develop cracks, and can suddenly fail at any time. This applies to tyres that have been kept in storage, even if they have never been fitted to a vehicle. The DOT manufacture date on the sidewall should always be checked and the replacement guideline of 5 to 6 years maximum, or 10 years absolute limit should always be followed.