Safe Tread Depth

Test of worn tires

A self-explanatory tire test was performed last year by our favorite AUTO BILD publication, in size 225/45 R17. The test experts made a vivid presentation of most common scenarios of emergency situations.

Which tire is safer?
Which tire is safer?

The test involved the top three tire makers — Michelin, Continental, and Goodyear. Their products were tested at different tread depth. The wet tests were also performed at several different speeds.

Here is what they got:

Stopping distance at 80 km/h (standard city speed)
Stopping distance at 80 km/h (standard city speed)
Stopping distance at 120 km/h (standard highway speed)
Stopping distance at 120 km/h (standard highway speed)

If a 1.5 increase in the stopping distance in the city in the rainy weather might still be not much of an argument for somebody, then what do you say to the whopping 158-meter stopping distance (+263%) on the highway? And, mind, these are the top tire makers. The budget tires are likely to perform even worse.

The tire makers’ advice

While most manufacturers stick to the standard minimum legal tread depth of 1.6 mm, Continental, being the only exception, calls on motorists to replace their tires at 3 mm.

While everybody criticizes Continental by saying that this call to action is simply motivated by the desire to boost their sales figures, Continental does have a point. This company understands that there is no fooling with physics, and no matter how good a worn tire is, it simply cannot dispel as much water from the contact area as a new one. What do you think about that?