The "Deutsche Umwelthilfe DUH" (So far we have noticed by warning against car dealers on Facebook) raises serious allegations against the car manufacturer Opel. During tests, an Opel Zafira with a 1.6 liter diesel engine should have been noticed by greatly increased NOx levels.
Is Opel cheating on nitric oxides?
The Volkswagen scandal has not only alarmed the automotive industry, almost every test bench and environmental expert is now on the hunt for the “fraudsters” and “polluters”. Deutsche Umwelthilfe is known for its particularly critical opinion on diesel engines. Now the DUH has tested an Opel Zafira 1.6 CDTi together with a Bern University of Applied Sciences and the Swiss emissions test center. The vehicle, which was just a few months old, had 6.000 km on the clock at the time of testing.
17 times the values?
In the The DUH has readings published from six test runs. According to DUH, the result says: As soon as the vehicle detects that it is on a test stand, it achieves up to 17 times the NOx emissions.
In order to simulate the “test bench environment” for the vehicle, the DUH has resorted to very simple means. A roller dynamometer of the brand “AFHB GSA 200” with the possibility of testing 4-wheel-driven vehicles was repeatedly converted between 4-wheel and 2-wheel operation in several test stand runs.
The results recorded by the DUH allow the conclusion in 2 x 3 runs: The Opel Zafira recognizes the test bench and switches to a “test bench mode” with correct emission values during the “test bench run” (only the front wheels turn). As soon as the four wheels roll on the test bench, significantly increased NOx emissions are detected.
The Opel Zafira 1.6 CDTi is equipped with an SCR after-treatment. The urea system was also paralyzed on a test basis by the test stands. The DUH claims: That does not lead to an error message in the engine control unit.
The results suggest that the tested Opel Zafira would, once it detects a test bench environment, disable SCR treatment.
Test results and open questions
However, the results of the DUH must be questioned on several points. On the one hand, not all test bench runs (at least 20) were published, only 2 x 3 were selected. On the other hand, according to the DUH, the test bench runs were carried out in conjunction with the electrical consumers. However, the NEDC standardization does not provide for this. Even if the DUH has tried to create a realistic relationship between the test bench, NEDC and exhaust gas values - there is no statement as to when the test vehicle was moved with the consumers and when not. It is also important to know where the 14 other test protocols are and what their results are. In addition, it is not recorded in which test runs the SCR system was deactivated.
The DUH is not known for an objective view of the automotive industry in general and the diesel in particular. The one-sided presentation of the measurement result also gives the impression of publishing here only what suits your own opinion.
But Opel is in the duty!
One thing the DUH has already done. The diesel scandal will this weekend, starting from Wolfsburg, also employ the Rhine-Main area and the Opel headquarters in Rüsselsheim. One can only advise all press departments to exercise maximum transparency. Opel is now in the duty.
And this question also needs to be clarified: Why did the Zafira engine control unit not save an error message after the DUH manipulated SCR operation?
Opel affirms in a first opinion, a manipulation does not take place!
Opel rejects the allegations of the German environmental aid sharply.
“The following applies to all of our cars as before and without restriction: software developed by GM does not have any features that determine whether the vehicle is being subjected to an emissions test. In response to the request from Deutsche Umwelthilfe, our engineers have currently carried out and recorded additional tests with a corresponding vehicle (Zafira with 1.6-liter Euro 6 diesel engine) in accordance with the statutory regulations - on both a two-roller and a four-roller test bench . The result: the values are absolutely correct and within the framework of the legal requirements. That means: the allegations are clearly false and unfounded. "
Here you can download the test report as pdf - click -
Cover picture: Copyright "Holzmann / DUH"
