The braking distance for worn tyres is up to three times longer in wet weather. Research also shows that aquaplaning can begin at speeds that are clearly slower than normal road speeds. Drivers should monitor the condition and inflation pressures of their tyres regularly and not only during the tyre changing season. Safe summer tyres should have a minimum tread depth of four millimetres and they should be no more than six years old.
“Poor tyres are among the major traffic safety risks in summer traffic. The grip on worn tyres will collapse in wet weather, which will jeopardise safety especially under extreme conditions,” said Matti Morri, Technical Customer Service Manager for Nokian Tyres.
In recent tests conducted by Tekniikan Maailma (5/2018), worn tyres started aquaplaning at speeds as low as 75 km/h. The best new tyre in the test only started aquaplaning at 88 km/h.
“The test tyres that were determined to be dangerous were nevertheless completely legal, that is, they had a tread depth above 1.6 mm. The driver has full responsibility for monitoring tyre wear. In addition to tread depth, you should also check the tyre for cracks and regularly verify that the inflation pressure is correct. As the tyre gets older, its characteristics will also weaken, so you should bear in mind that the maximum service life is six seasons. For the family’s second car and other cars that are used less often, you should ensure that the overall age of the tyre is less than 10 years. This is easy to check on the tyre sidewall where you can find the tyre’s year of manufacture,” Morri said.
Maximise service life by rotating tyres from the front to rear
In order to maximise safety and save money, you should ensure that the tyre does not wear down abnormally. A tyre that only wears down on the inner or outer shoulder is a symptom of something being wrong. It is often a sign of excessively low inflation pressure, incorrect alignment or worn shock absorbers.
“Abnormal wear will have a direct impact on handling. Unless you act on time, the wear may even reach the tyre body and destroy it completely. For example, you should remember to check your tyre pressure once every three weeks. When setting off on longer trips or transporting heavy loads, you should increase the tyre pressure in proportion to the load,” Morri said.