The #Dieselgate splashed to Opel and General Motors, according to some independent testing


Laboratory exhaust emissions of the University of Bern, department of Applied Sciences (Switzerland)

We should be cautious with the conclusions of the study, which or believe to Deutsche Umwelthilfe, or believe to General Motors, no half measures. The environmental organization, linked to Transport & Environment, has put in a bank of rollers to an Opel Zafira Tourer 1.6 CDTI, which meets Euro 6, to measure their emissions of oxides of nitrogen (NOx). The car has 6,000 miles and is enrolled in August.

The tests have followed a mechanism similar to those that have been made with models of Volkswagen in the united States, with a roller that moves only the front wheels, and with a double roller so that they move all. why? If you move only the front, you can hunt a programming hides that work in conditions of approval.

In the test of the front roller, the motor has complied with what is expected of him, below 0.08 grams of NOx per kilometer, which is corresponding to the regulations. When you do the testing with double-roller, then emissions have reached four times the legal limit. According to DUH, there is no reason to a technical level that justifies this discrepancy, except a potential programming hides, or “defeat device”.


According to a press release sent by General Motors, after knowing these results, there is no change in the emissions of a car exactly the same, regardless of if you were testing with a roller or two. Is more, GM categorically denies that its cars to detect if you are being subjected to an emissions test in the laboratory.

But we continue with the conclusions of the report. By doing a few tests that are out of the cycle of usual test, NOx emissions have dropped out of the threshold of measurement. This has been detected speeding up to 150 km/h, with the rear wheels stops (a roller). DUH believes that the systems anti-pollution temporarily disabled for the engine to have better performance in that situation.

the latter seems reasonable, since in the test cycle of the approval, any modern engine is used at 100% of its possibilities, or make acceleration strong. If it requires the maximum power to the motor, you can understand that does not comply with the legal limits of emissions, although at the level of ethics or morality that does not seem to us so well. not like, do not step on the accelerator to fund, because so it must be in 100% of the fleet.


We may doubt if DUH has acted in good or bad faith, but I must say that the press release of the organization has included the response of General Motors, which coincides with the official press release from the company, at least extracts of the same.

it Would be totally normal for this model of Opel, as well as any other of this brand (and any other) to comply with the emission limits in the lab, but then is unable to stay below 80 milligrammes of NOx per kilometre in real-life situations of driving.

In that sense, neither GM nor Opel have nothing different to others

Now, if by using the scientific method, we recreate the same circumstances test, and the emissions return to be different depending on whether the car is tested on a bank of simple roller or a double, then everything changes. Talk about a programming hidden, the same reason that it is crucifying to Volkswagen, and General Motors would have a problem of enormous magnitude.


The first is legal, although we don’t like (the car is compliant in terms of test), the second is not legal (programming hidden). The results of the test have been submitted to the competent authority in terms of approvals in Germany, the KBA, to do their own tests. In the event that the results come out the same DUH, General Motors is going to have problems in Europe.

The Opel Zafira 1.6 CDTI incorporate, in addition to the famous catalyst NOx (LNT), the selective catalytic reduction (SCR) based on urea or AdBlue. These systems are the most effective to date to keep the emissions of NOx… if they are active. The vilified engines Volkswagen EA189 have one or two things, and they work at full performance only in terms of test gas.

The figures provided by DUH suggest the same that, depending on that the rear wheels are moving or not (test conditions gas) systems, anti-pollution are not equally effective. General Motors denies it all. We will have to wait for the report of the KBA, which give reason to one, or to other.

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