Photo: Pawel Loj (Flickr) CC BY
Has spent more than half a year since Volkswagen admitting that you have placed on the roads millions of cars that do not meet the emission regulations regarding nitrogen oxides (NOx). The entire industry was put in the spotlight of the media, suspecting that it could be a practice more widespread.
today, still has not been shown that another group automotive has cheated to mislead the authorities of approval. There are suspicions about several manufacturers, but at an empirical level only the Volkswagen Group has done. In the united States the investigations are not finished.
upon detection of a test cycle emissions, the TDI engines from Volkswagen -principally the family EA189 – they did their best to lower their NOx emissions within the legal limits. In other conditions, the engines pollute the most, not by choice, but by criteria of a technical nature.
from 2017 will change the rules of the game, allowed a higher NOx emission, but in and out of the lab. At net level, the emissions should come down about now
¿There is a relationship between the consumption and the pollution?
In a diesel engine modern, to pollute it little, you need to use maps of injecting more rich, that is to say, put more diesel in the cylinder to burn better in the mix and achieve higher combustion temperatures. This implies a greater consumption of fuel. There is also that use sophisticated systems, such as LNT or SCR for reducing emissions of exhaust gases.
The diesel engine, by its very nature, emits many oxides of nitrogen because it compresses a lot of air, and this is very rich in nitrogen. If you use pure oxygen, the combustion would be much more clean, but that filtering would be too expensive and not very efficient. On the other hand, can also be affected benefits to the poor.
The engineers of the Volkswagen Group preferred that the engines have better performance or increased mechanical reliability, instead of pollute less. And to be able to sell all those cars, it had to deceive the authorities, by detecting test cycles, so that the motors are “portasen well” only in those conditions.
The three main european countries have tested a multitude of models from different manufacturers, looking for more stations prepared to deceive. United kingdom analyzed 37 models of 20 different brands. France has tested 52 models of 15 brands. Germany has done so and his report should be out in very little time, since it was announced for the end of April, the month that ends today.
The preliminary conclusions are the same: the competition, Volkswagen has not made traps, and does not detect evidence of approval. That yes, there have been detected levels of emissions of carbon dioxide (CO2) and oxides of nitrogen (NOx) at levels greater than the legal, when cars are not inside of a laboratory.
The discrepancy between what the cars stack on a site and in another is due to multiple factors, we can summarize that, within a laboratory, conditions are very stable and easy to reproduce. engineers have been able to calibrate the engines to give the best result under these conditions, which is what prompted the legislation. They contaminate more on the outside we may like it or not, but to comply, have complied with the rules.
The regulation of type approval european cycle NEDC, you have different tolerances that the manufacturers take advantage of in your benefit to advertise lower intakes (directly proportional to CO2) or emissions of NOx low, even some talk of engines ecological. For example, it allows systems to anti-pollution may not work in some conditions, such as in a cold boot, to protect the engine and the auxiliary systems of the corrosion.
The final conclusion is that diesel engines have proved to be a gigantic fraud in the field of emissions, because in real life they are polluting more than expected, and that has a significant relationship with the health of millions of european citizens. NOx is related to the increase in tropospheric ozone and a multitude of respiratory diseases that degenerate in premature deaths. we are talking about thousands of people per year, many more than die in traffic accidents.
Surely we have already known the heyday of this type of mechanical. The consumer is the worshipped for its low consumption, its near parity with gasoline engines in performance, durability, etc., In the last few years it has been seen that the durability is not that which was, and are highly polluting. The gasoline has returned to gain ground, and there are alternatives to both fuels.