Oliver Krischer, a leading member of the Green Party, told the news agency DPA that the allegations “take the emissions scandal into a new dimension.”
Such harsh criticism of the auto industry is unusual in Germany, and it illustrates the degree to which public opinion is turning against the carmakers. Motor vehicles are the country’s biggest export, and Volkswagen, Daimler and BMW are among Germany’s largest employers.
In its statement on Sunday, BMW said that discussions with the other carmakers had been about how to ensure that customers would be able to buy refills of a chemical needed for pollution equipment in diesel vehicles. The chemical, a urea solution sold commercially as AdBlue, is sprayed into the exhaust to neutralize harmful nitrogen oxides.
“From a BMW Group perspective, the objective of discussions with other manufacturers concerning AdBlue tanks was the installation of the required tanking infrastructure in Europe,” BMW said.
The German magazine Der Spiegel reported on Friday that the carmakers agreed in 2006 to limit the size of the tanks used to hold AdBlue to save space in the car that could be used for sound systems or other features. Volkswagen has admitted that its vehicles were programmed to ration doses of AdBlue, leading to excess emissions. Der Spiegel said it had seen documents that were part of an antitrust investigation.
BMW said its latest models were clean, despite a relatively small AdBlue tank, because they combined two types of pollution technology: a system that uses the AdBlue spray and a separate catalytic converter that traps nitrogen oxide molecules.
In a tacit admission that older vehicles pollute too much, Daimler, Volkswagen’s Audi division and BMW have announced plans to upgrade software on diesel vehicles across Europe to reduce emissions. The three carmakers have said in recent days that they will modify more than four million vehicles, including three million Daimler vehicles, 850,000 Audis and 350,000 BMWs.