German report on VW diesel scandal finds large gap between lab and real-world NOx emissions for German automakers; 630K vehicles in voluntary recall
A German inquiry launched as a result of the Volkswagen diesel emission scandal has found that there is a large gap between homologated emissions values from lab testing and real-world driving results for all German manufacturers.
German Transport Minister Alexander Dobrindt, who presented the results of the inquiry on Friday, said that only Volkswagen had used a software defeat device that detected test cycles (Prüfzykluserkennung) and altered calibrations accordingly. However, other manufacturers do use a thermal window (Thermofenster) technique that cuts back on emissions treatment at certain temperatures—presumably to protect the engine against damage.
Although the Thermofenster technique is legal, investigators doubted that the chosen thermal windows are fully justified by engine protection, Minister Dobrindt said. Manufacturers concerned have been asked to take measures to restrict the thermal window to what is actually necessary. All affected German manufacturers have declared in writing that they will perform the required optimizations.
Manufacturers who use the Thermofenster technique will voluntarily recall approximately 630,000 vehicles produced in Europe for optimization of the emissions control. The German Kraftfahrt-Bundesamt (KBA) (Federal Motor Transport Authority) will check the improved emission control concepts for their effectiveness.
Prior to KBA approval of the optimized control software, a manufacturer must describe and explain the specific function in the control software to the KBA, as well as the reasons the manufacturer believes the engine protection is necessary.
The KBA will validate this. When in doubt, KBA will carry out additional measurements on the road with portable emission measurement technology (PEMS).
For the report, KBA investigators checked emissions from 53 models of Euro 5 and Euro 6 diesels. Measurements were taken on both the dyno as well as on the road.
Bericht der Untersuchungskommission Volkswagen (Report of the commission of inquiry, German only)