Tire is the most important part of the car. It is the first safety barrier. If you understand the meaning of "235/55 R19", you can choose the right "shoes" for your car, but this is not enough. Not suitable for cars, not meet the needs, but also have to look at the "wear index", "wet adhesion" and other key indicators, we do not talk about too much boring data, mainly to explain the common but easily overlooked tire problems.
This problem seems illogical. The tread of the old tires has almost worn out to the indicator line. How can the new tires have a shorter braking distance than the tread? Michelin and some overseas tire testing organizations have conducted special research. The ground braking distance of the old tires of 100-0km/h is about 4 meters less than that of the new tires. The reason is actually very simple.
First of all, the conclusion is that there is no absolute relationship between the depth of the tread and the braking distance. Old tires perform better in terms of braking distance because the almost flattened tread makes the contact area between the tire and the ground larger, resulting in greater adhesion. Of course, the new tires have deeper treads, and the drainage is naturally better than the old ones, and the handling on wet roads and rainy days will be better.
Under the premise that the wear indicator line is not reached, the safety of the tire is not absolutely related to the tread depth. The most important point is that when the tire wears to a certain extent, it has lower rolling resistance (not adhesion) than the new tire. Therefore, the fuel consumption can be reduced by about 5%, and the 5% should not be underestimated.