PHOENIX — On the heels of legal victories against Volkswagen, the Attorney General’s Office is now accusing Mercedes-Benz and parent company Daimler AG of lying to Arizona consumers about their own clean-burning diesel engines.

The lawsuit filed this week in Maricopa County Superior Court contends that the German automaker marketed its BlueTEC diesel vehicles as converting nitrous oxide emissions into “pure, earth-friendly nitrogen and water,” producing “fewer greenhouse gases than gasoline” and exceeding legally required emission standards.

But what the company did not disclose, the lawsuit states, is that these BlueTEC engines were programmed to turn off or reduce the emission-reduction systems during normal driving.

“As a consequence of this critical concealed material fact, consumers are unaware that — contrary to defendants’ representations — the affected Mercedes vehicles are not clean diesels and, to the contrary, emit enormous amounts of NOx pollutants into the atmosphere,” wrote attorney Rob Carey. His law firm, Hagens Berman Sobol Shapiro, was retained by the state.

The lawsuit seeks reimbursement for potentially up to 10,000 Arizonans who purchased or leased certain Mercedes vehicles between 2007 and 2016, as well as $10,000 in penalties for each violation.

Calls to company officials for comment were not immediately returned.

Diesel engines can produce more torque than standard gas engines because they operate at high temperature and pressure.

“But this greater energy and fuel efficiency comes at a cost: Diesels produce dirtier and more dangerous emissions,” the suit states.

These include oxides of nitrogen — known as NOx — which produce compounds that react with sunlight to form ozone, linked to serious respiratory dangers.

The vehicles sold did, in fact, pass federal emissions tests.

What caused people to take notice, however, was the discovery several years ago that Volkswagen, marketing its own clean-diesel vehicles, had programmed them to pass the tests and then shut off the emission-reduction systems. VW eventually pleaded guilty to criminal charges, agreed to pay $4.3 billion in penalties to the EPA and another $17.5 billion to resolve civil lawsuits, including $40 million to Arizona consumers .

This new lawsuit says that Mercedes designed its vehicles in a similar fashion, allowing them to test as meeting federal emissions standards in laboratory situations that did not match what motorists actually face.


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