Fiat Chrysler is being sued for an alleged defect in the emissions systems of some trucks that can result in a 25% drop in fuel economy, according to a lawsuit filed by the firm Hagens Berman.
The lawsuit says Fiat Chrysler sold hundreds of thousands of 2013 to 2017 RAM 2500 and 3500 pickup trucks with faulty emissions systems.
Owners who brought their trucks in for a repair of the systems found that the fix resulted in dramatically lower fuel economy.
Fiat Chrysler is also being sued by the federal government for allegedly cheating on emissions in some other Ram trucks and some Jeep Grand Cherokees. That lawsuit says the automaker installed illegal software that turns the emissions controls on during government tests, and partially off during normal driving.
The new lawsuit is just the latest in a series of private and government lawsuits filed against Volkswagen, Mercedes, Fiat Chrysler, and General Motors as well as supplier Bosch over emissions cheating in cars and trucks with diesel engines.