BMW of North America is being sued by U.S. drivers for installing software designed to cheat diesel-emissions tests. According to the complaint filed Tuesday in New Jersey federal court, the emissions-cheating software allegedly masks pollution in 2009-2011 X5 and 335d diesels up to 27 times the legal standard, and 3 times the legal standard on average.

“At these levels, these cars aren’t just dirty — they don’t meet standards to be legally driven on U.S. streets and no one would have bought these cars if BMW had told the truth,” said Steve Berman, the plaintiffs’ attorney who has filed similar claims against Ford Motor Co., Mercedes-Benz, Fiat Chrysler Automobile, General Motors and Volkswagen.

“The vehicles’ promised power, fuel economy, and efficiency are obtained only by turning off or turning down emission controls when the software in these vehicles senses that they are not in an emissions testing environment,” the suit said.

Kenn Sparks, a spokesman for BMW North America, said in an emailed statement: “As a matter of principle, BMW Group vehicles are not manipulated and comply with all respective legal requirements.”