The EPA issued a second notice of violation of the Clean Air Act to Volkswagen today, accusing the automaker of using software to cheat emissions testing with 3.0-liter diesel engines in recent VW, Audi, and Porsche cars. The EPA says that covers about 10,000 passenger cars sold in the US since 2014, which were emitting up to nine times the legal limit of smog-produced nitrogen oxide pollutants in real world driving.

That's on top of the 482,000 cars with "defeat devices" VW has admitted it sold in the US since 2008, all of which had 2.0-liter, 4-cylinder engines. Since the EPA can charge VW up to $37,000 for each instance of cheating, this new batch of cars could add $370 million to VW's fines. That brings the potential total up to $18,204,000,000. Worldwide, VW has sold more than 10 million cars with the illegal software, and it's unclear how fines and legal repercussions will play out in various countries.

“VW has once again failed its obligation to comply with the law that protects clean air for all Americans,” says Cynthia Giles, from the EPA's enforcement arm. This new batch of cars includes the 2014 VW Touareg, 2015 Porsche Cayenne, and 2016 Audi A6 Quattro, A7 Quattro, A8, A8L, and Q5.

VW released a statement denying the allegation, saying "no software has been installed in the 3-liter V6 diesel power units to alter emissions characteristics in a forbidden manner."1

1Updated November 3, 2015 at 10:53 EST to include Volkswagen's response.