The study was reportedly published in cooperation with both the University of Applied Sciences in Bern, Switzerland, and the International Council on Clear Transportation. The latter is the same organization that commissioned the investigation into similar issues with Volkswagen's diesel engines. The Renault study was undertaken on an Espace van with a 1.6-liter diesel engine that, despite being Euro 6-certified, was found to emit up to 2.06 grams of NOx per kilometer, or more than 25 times the legal limit. That study has yet to be independently verified.
If the allegations prove to be true, Renault wouldn't be the first automaker caught out by such third-party testing. In the wake of the VW scandal, DUH issued a similar report alleging violations by the Zafira, a comparable minivan produced in Europe by General Motors subsidiary Opel. Along with other parties, DUH and the ICCT are calling on European officials to mandate stricter testing procedures that would close loopholes left open under current testing regulations. Such reported loopholes currently allow automakers to optimize the engines to run at artificially low temperatures, strip out standard equipment to reduce the vehicle's weight, tape up door joints, and fit bald tires with lower rolling resistance.
UPDATE: Renault issued this statement in response to the DUH's findings:
Renault disputes findings of German association Umwelthilfe on Espace emissions
- As previously stated, Renault reiterates that Espace complies with applicable regulations, just as all its vehicles.
- The test procedures used by the University of Bern are not all compliant with European regulations. The report shows important variations in test findings which are not conclusive and require "additional measurements".
- Renault is endeavoring to fully understand the tests in detail especially in light of the findings published in August 2015 by the independent German institute ADAC which tested the Espace model and concluded that it complied with regulations.