Tires are a key element in the safety of a car as they are the only point of contact of the vehicle with the asphalt. For this reason, its maintenance is very important, although the data from the ITV station employers, Aeca-ITV, show that motorists do not pay too much attention to them: two out of 10 vehicles that fail inspection do so due to poor condition. the tires.
The tires must be replaced when they wear out, as a general rule between 40,000 and 60,000 kilometers, although it varies depending on various factors. The quality of the tires, the type of car or the style of driving influence wear, which is why the brands recommend inspecting the vehicle's tires six years after they were fitted, even if only a few kilometers have been traveled.
One of the points that must be reviewed is the drawing of the cover to make sure that it has the regulatory depth. The regulations establish that it must be at least 1.6 mm, although manufacturers advise that the figure should not fall below 3 mm.
One of the most widespread tricks to check is to place a one euro coin in the groove of the tire and see if the depth of the groove covers the gold edge. If the edge is not hidden, it is recommended to change the tire.
However, this recommendation to measure the legal depth of the tire tread with a one euro coin is "totally inadvisable", both for reasons of efficiency and sustainability, says Fesvial (Foundation for Road Safety), based on a study.
This organization considers that this widespread recommendation may be "an unfounded hoax, at best, when not an intentional manipulation to force us to change tires before the end of their useful life within legal and safety parameters" .
Fesvial explains that the edge of a one euro coin measures more than 3 mm, double the legal minimum depth of 1.6 mm, so he considers that we should not follow this widespread advice because it has not been proven that these tires are not safe.
Rather, it considers that it is a practice leading to the planned obsolescence of tires, according to the conclusions of a report published by the EY audit firm on the economic and environmental impact of the generalization of the premature withdrawal of tourism tires in the Union. European.
To check the condition of the tires, Fesvial proposes to replace the one euro coin trick with other tests that provide greater reliability to users. He warns that as some tires lose efficiency quickly while others maintain their performance at different levels of wear, "a tire with 1.66 mm (depth) can brake better than another tire with 3 mm (depth)."
The results of the studies on accidents do not establish a relationship between the increase in the depth of the tread of the tires and a change in the number of accidents. Fesvial assures that the statistical analyzes based on tread depth and accidents do not recommend a change in the regulations, thus recommending that the 1.6 mm limit be maintained.
Fesvial ensures that changing tires early following the manufacturer's recommendation to do so when the pattern is less than 3 mm would entail a high economic cost. The Foundation estimates that it would mean, each year, a bill equivalent to 800 million euros for EU motorists due to increased fuel consumption and another 6.1 million euros for more frequent tire purchase costs. So I totally discourage it.
