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Deutsche Umwelthilfe has raised serious allegations against the car manufacturer Mercedes: A "controversial software report" has disclosed the mode of operation of previously unknown shutdown devices in exhaust gas purification.
According to the Federal Managing Director of Deutsche Umwelthilfe, Jürgen Resch, the Daimler Group has been convicted of using other illegal shutdown mechanisms in addition to the well-known temperature-controlled shutdown devices for nitrogen oxide cleaning of the exhaust gases.
Tobias Piller
Editor in business.
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The report and the press release from Deutsche Umwelthilfe are part of a legal battle that, according to Daimler, has so far led to 16,400 trials at the lowest court level and 900 trials at the higher regional courts.
"A multitude of technical requirements"
Deutsche Umwelthilfe had a Mercedes E-Class from 2015 tested for its report, which was certified according to "Euro 6".
The Euro 6 limit values were introduced from 2015 and reduced the limit for nitrogen oxide emissions to 80 milligrams per kilometer.
From 2015 to 2019, the limit values for Euro 6 were only officially determined in the test laboratory under specified conditions and with a specified driving cycle.
There has only been a road test of the cars since 2019.
The limit values of the "Euro 6d" category have been in effect since 2021, with a more demanding test cycle for the laboratory and a road test in which the limit value for the laboratory may be exceeded by a maximum of 50 percent, i.e. a maximum of 120 milligrams of nitrogen oxide per kilometer.
Deutsche Umwelthilfe, on the other hand, tested its test car from 2015 in a variety of test situations that occur in normal road traffic.
It was found that in many situations, for example at high temperatures, at high engine speed or during a cold start, the exhaust gas cleaning system does not work optimally.
The engine control always switches to a work program that does not allow optimal exhaust gas cleaning.
It is said of Mercedes that when developing the exhaust gas purification system, the engineers were always faced with the challenge of “reconciling a large number of technical requirements and practical decisions with abstract legal requirements”. There was also scope for legal interpretation. One example is the accusation by environmental aid that a nitrogen oxide catalytic converter is not injected with sufficient quantities of Adblue as a reactant in all situations and that the cleaning does not work optimally. At Mercedes, they say that they definitely wanted to avoid the chemical reaction from leaking out toxic and smelly ammonia. Mercedes claims that 95 percent of all lawsuits were won at the lowest court level,likewise 897 of 900 proceedings at the Higher Regional Court.