FRANKFURT -- Daimler said a U.S. class action lawsuit alleging that its Mercedes-Benz diesel cars use a device that turns off pollution controls is unfounded.
Mercedes uses a shut-off device in its BlueTec clean diesel cars that causes the vehicles to violate U.S. emissions standards when run at cooler temperatures, according to a lawsuit filed in a federal court in New Jersey by consumer-rights law firm Hagens Berman Sobol Shapiro.
Daimler spokesman Joerg Howe called the claim "baseless" and said the company would review the complaint and defend itself. "All our vehicles comply with regulatory frameworks,” Howe said. “All our vehicles are certified according to the laws."
The allegation was made by a Mercedes owner in Illinois, who claims the automaker uses the device to turn off a system meant to reduce NOx exhaust emissions.
The lawsuit accused the automaker of knowingly programming its clean diesel vehicles to emit illegally high levels of NOx that were 19 times above the U.S. standard, with some instantaneous readings as high as 65 times more than the U.S. limit. The device turns off pollution controls at temperatures below 50 degrees Fahrenheit (10°C), according to the complaint.
Hagens Berman said it based its allegation in part on an article appearing in this month’s edition of the German magazine Der Spiegel. The magazine reported that Mercedes admitted the shut-off is done to protect the engine, according to the complaint.
The law firm also cites a study conducted by independent testing agency TNO for the Dutch Ministry of Infrastructure and the Environment, which said that in real-world testing, the Mercedes C-class 220 emits more nitrogen oxide than measured in laboratory results.
"Mercedes never disclosed to consumers that Mercedes diesels with BlueTEC engines may be 'clean' diesels when it is warm, but are 'dirty' diesels when it is not," according to the complaint. "Mercedes never disclosed that, when the temperature drops below 50 degrees, it prioritizes engine power and profits over people."
While it's typical for real-world results to differ from lab tests, Monique de Geus, a spokeswoman for TNO, said its tests showed that many models sold in Europe had emissions that were much higher than allowed. Mercedes's BlueTec models were among those tested, she said.
"It's normal that emissions can be higher but not in the range they are now," de Geus said, without referring to specific models. "They are a lot higher."
Even if Mercedes is able to make the cars compliant with emissions standards, those who drive them will suffer harm because the vehicles will not perform as promised or advertised, Hagens Berman said in the complaint. The suit is seeking a court order compelling Mercedes to recall the affected models or replace them for free, in addition to unspecified damages.
The law firm is proposing to represent a nationwide class that includes all U.S.-based residents and entities that bought or leased an affected vehicle as of this month. Among the enumerated models are Mercedes's ML320 and 350 sport utility vehicles, its E- and S-class cars, and GLE crossovers.
The allegation mirrors similar claims that have beset competitor Volkswagen. Hagens Berman has been active in pursuing consumer cases against VW.
Diesel cars have been in the spotlight since VW admitted in September it had rigged U.S. diesel-emissions tests and up to around 11 million vehicles worldwide could have illegal software installed. The U.S. Justice Department is suing VW for up to $46 billion for alleged violations of environmental law.
Last month Renault shares plummeted after news of raids by French investigators as part of a probe into vehicle emissions. Renault recovered much of its lost market value after France’s Environment Minister Segolene Royal said no fraudulent systems had have been discovered and that shareholders and employees should "rest easy."
Reuters and Bloomberg contributed to this report
CORRECTION - An earlier version of this story misstated which models are involved in the lawsuit.