More tread means more safety

DEKRA Info March 2018

More tread means more safety: Summer tires

Summer tires

Springtime is also the time to think about switching from winter to summer tires. Christian Koch, tire expert at DEKRA, points out what motorists need to pay attention to before they replace tires.

Why does a car need summer tires? Summer tires have been optimally configured for the warmer months. “The tread is specially designed to achieve short braking paths on dry road surfaces, but also to transport water away from the tire on wet road surfaces,” says the expert. “Moreover, the rubber mix is configured so that it can withstand the extreme temperatures of hot summers and friction.”

How much tread is required? Even though the law requires a minimum of 1.6 millimeters of tire tread, Koch recommends a tread depth of 3 millimeters when fitting new tires. The reason for this is that “Adherence deteriorates significantly in bends as tread depth reduces, especially in the wet. This means the braking path lengthens and the vehicle is more prone to aquaplaning. So, more tread means more safety.”

How old? The risk of failure increases once the tires are over seven years old. Consequently, an expert should take a look at the tires. The age of the tire can be seen from the four-digit DOT date code on the tire sidewall. The number sequence 1711, for example, means that the tire was produced in the 17th calendar week of 2011 and would be about seven years old in the spring of 2018.

Check for damage: “If a tire displays cracks, incisions or even bulges, a trained eye should check whether the tire can still be used,” says the expert. Non-uniform or one-sided wear to a tread indicates incorrect chassis setting or defective shock absorbers and therefore that it was time for a visit to the garage.

Change correctly: The tires between front and rear axle are to be changed in pairs on a regular basis so that they wear away evenly. However, do not change the tread direction of the tires in the process. As far as possible also include the reserve tire in the change.

Correct pressure: After the change, adjust the tire pressure according to the recommendation of the manufacturer. Afterwards, it is necessary to check the pressure on the cold tire about every other week and before every lengthy journey. Insufficient pressure means a greater risk of failure, poorer road holding and more wear.


Tilman Vögele-Ebering

Press officer Industrial


Phone +49.711.7861-2122

Fax +49.711.7861-742122

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