The Euro 7 standard will define the new emission limits allowed for future vehicles in the European Union. Until now, all eyes have been focused on combustion vehicles but there is an unexpected protagonist: disc brakes.
euro 7. With each European emission regulation for vehicles, the restrictions on them are more severe. These regulations are the same ones used by the DGT to classify vehicles according to environmental stickers and which are also used (and will be used) by town councils in their low emission zones (ZBE).
At the moment, the definitive maximum limits for cars with combustion engines have not been defined, but it is expected that, in practice, the new standard will mean the end of non-electrified vehicles. The margins that are managed, there is talk of going from 80 mg/km and 60 mg/km of NOx for diesel and gasoline, respectively, to maximums of 30 mg/km and 10 mg/km. Unattainable figures for a vehicle powered exclusively by a combustion engine.
Not just the exhaust. When pollution is considered for each vehicle manufactured, reference is not only made to the fuel or energy consumed during its useful life. Electric vehicles, for example, are more polluting during their manufacture, especially weighed down by their batteries. And to this we must add the large cable harnesses, the materials that cover the passenger compartment or the tires.
Invisible. Among this “invisible” contamination, which is not usually paid much attention to, is the dust released by the brake discs. In fact, among the official documents to promote the future Euro 7 standard, it is specified that the European Union seeks to “limit the emissions of PM2.5 and nanoparticles from all types of combustion engines and brakes in conventional and electric vehicles.”
With each braking, cars emit small particles that are referred to as “PM2.5 emissions”. These are the smallest and can penetrate deep into the lungs and enter the bloodstream, causing cardiovascular, cerebrovascular (stroke) and respiratory impacts, as well as contaminating land and water. In fact, the WHO ensures that 99% of the world’s population breathes air that exceeds the quality limits recommended by the organization.
goals. According to the National Institute of Applied Sciences of Lyon, brake pads cause 20,000 tons of dust in suspension every year, of which 9,000 tons remain in suspension in the atmosphere.
The commitment of CLOVE (Consortium for Ultra-Low Vehicle Emissions, for its acronym in English), which serves as advice for the future Euro 7 standard, is that the polluting emissions of the brakes are reduced between 40 and 60%. Transport & Environment considers this measure very insufficient and believes that, at least, it is necessary to reduce polluting emissions from brakes by between 85 and 90%.
How to get it? The great challenge here is to achieve a less polluting brake system that, at the same time, obtains results that are just as good as the current ones. Copper reduction is key. In fact, brands have been limiting its use for years and the goal is to make it disappear from the brakes completely.
Porsche also has its own system where it is necessary to coat the brake disc with tungsten carbide. According to their data, they get almost as good braking as with ceramic brakes and wear and dust emissions are 90% lower than traditional disc brakes. Another, less imaginative option is, plain and simple, to place a tank to collect the particles released during braking.
Photo | Benjamin Brunner
George is Digismak’s reported cum editor with 13 years of experience in Journalism