We thought that gasoline cars were much cleaner than diesel. We did not have the effect of the sun

For every 100 cars that are sold in Spain, just five are diesel.

They are the latest data we have in Spain of registration, which reflects to what extent the diesel (despite having market niches in which It is still profitable) It has become an almost banished fuel in our country.

And although it may be weird, it does not make 70% of the cars we bought were diesel moved. In fact, just over a decade ago. In 2014 the diesel lived his golden age. From its 70.06% market share It has plummeted.

There are numerous factors that explain the rise and fall of diesel. For years, its price was so cheap (in fact it is still subsidized) than each buyer He poured liter calculations consumed For every 100 kilometers to know how long it would take to make investment profitable since they used to be more expensive motorizations.

But over the years, emission regulations were drowning the diesel. Especially after the famous Dieselgate in which it was discovered that the Volkswagen Group (first defendant) and other companies trucan their emissions to offer data within the legality in the homologation exams to, outside them, contaminate more than allowed.

With Euro 6, diesel were put much more complicated since 2015. For sample, the comparison between the demands made to diesel engines compared to gasoline and that You can read in this extensive article of Xataka in which all the normative change was explained:

Limits for a gasoline engine

• CO (carbon monoxide): 1.0 g/km
• HC (total hydrocarbons): 0.10 g/km
• NOX (nitrogen oxides): 0.060 g/km
• HC + NOX (hydrocarbons and nitrogen oxides): 0.160 g/km (approx.)
• PM (suspended particles): 0.005 g/km
• P (number of particles): 6×10^11/km (6×10^12/km for three years for direct injection)

Limits for a diesel engine

• CO (carbon monoxide): 0.50 g/km
• HC (total hydrocarbons): 0.09 g/km (approx.)
• NOX (nitrogen oxides): 0.080 g/km
• HC + Nox (hydrocarbons and nitrogen oxides): 0.170 g/km
• PM (suspended particles): 0.005 g/km
• P (number of particles): 6×10^11/km

The problem is that, due to its own operation, A diesel is less pollutant in CO2 that a gasoline but expels many more particle emissions than They are very dangerous to the health of the human beinglike the Nitrogen oxides (NOX). Although the value was slightly higher for diesel, emission regulations were forcing manufacturers to squeeze the brain.

With Euro 5 the particle filter. From Euro 6, the Adblue. These measures ended up banishing diesel engines of smaller cars. Well because they contaminated too much or because innovations to be installed in them It was more expensive both the product that did not make it viable.

If we take into account the increase in the product, the bad reputation after the dieselgate and the innumerable statements On a rise in the price of fuel, now it is better understood The sudden drop in sales.

All this explanation makes sense. Do you remember that Euro 5 forced to mount particle filters in diesel cars? And that with the Dieselgate the cars reflected some emission figures that were not real?

A study now indicates something similar for gasoline cars. It is not that they are cheating, they point out that the emission regulations itself may not be enough to tell us how pollutants are our cars.

A little effective particle filter

In short, a particle filter is a kind of mesh that catches larger pollutant emissions before expelling them to the atmosphere through the exhaust pipe. Taking advantage of the heat of gases, the mesh takes temperature and burns the particles, reducing emissions.

That is a problem in the cars that start and stop every time or those that do many kilometers by city because the engine does not give time to take the temperature enough to burn these particles and the filter ends up collapsing, causing a somewhat expensive breakdown.

For some years, emission regulations have forced gasoline cars to also mont particle filters to get emissions not to exceed the allowed limits. However, as a gasoline engine works at a higher temperature, It is more complicated to fall into these types of situations.

However, a study published in Science Advances He has pointed out a problem: they are not enough.

The particle filter aims to reduce the Volume of fine particles that are expelled to the atmosphere, PM2.5. And they get it, according to researchers but that is not enough to ensure that their toxicity is lower. They point out in their study that it is not enough to measure emissions just after combustion, they should be studied how they behave once in the atmosphere.

And how do they behave?: Bad.

They point out that, once in the air, the experts expelled are exposed to sunlight and that they cause a series of transformations that make them remarkably more toxic to the human being.

They explain in Phys.org that the modification of the particles caused damage to the human DNA and in cells that we find in our bronchi. It is what they call “photochemical aging” that causes particles to increase their toxicity generating “oxygenated volatile compounds, such as carbonilos.”

In the article they point out that Dr. Mathilde Delaval, the first author of the study and researcher at Helmholtz Munich, says that “our study shows that we are missing a large part of the panorama by not considering How exhaust gases changeand become more harmful, after leaving the car. “

The study is partially financed by the European Union and in it they have intervened in one way or another universities and laboratories of Germany, Finland and Switzerland.

Photo | Nursultan Abakirov and Romanov Nick

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