This week brought confusion for General Motors and its German subsidiary Opel.
In Germany, GM's Opel has been denying allegations of illegal emissions-system-killing software in its diesel Zafira compact vans and its Insignia sedans, according to Bloomberg.
In the early '70s, the EPA reprimanded GM, Ford, Chrysler, American Motors, Nissan, and Toyota for building cars with devices that would "defeat the effectiveness of emission control systems under conditions not experienced during EPA s certification testing."
However, Opel doesn't currently sell cars in the US, and according to the Wall Street Journal, Under European law, auto makers are allowed to use so-called defeat devices to suppress emissions control under certain conditions to protect the engine, such as in colder temperatures to limit soot emissions to protect the particulate filter in the catalytic converter.
The company's CEO, Dr. Karl-Thomas Neumann, wrote earlier this week that the recent accusations against his company are misleading oversimplifications and misinterpretations of the complicated interrelationships of a modern emissions control system of a diesel engine.
Recently, the German government tested 53 car models for software similar to what was found in Volkswagen's now-infamous diesels.