By Paul Handley
The Volkswagen emissions-cheating scandal has widened, with US regulators saying the German automaker also included illegal "defeat devices" on its larger 3.0 litre diesel engines during the past three years.
Volkswagen had already admitted including the software, which cheats pollution tests, in its smaller 2.0 litre diesels equipped in some 11 million 2009-2015 model year cars worldwide.
But the Environmental Protection Agency said it had discovered in its investigation that various six-cylinder 3.0 litre diesel VW Touareg, Porsche Cayenne and Audis from the 2014-2016 model years and distributed in the United States had also been rigged with the software.
"We have clear evidence of these additional violations," said Cynthia Giles, an official with the EPA's Enforcement and Compliance Assurance office.
"VW has once again failed its obligation to comply with the law that protects clean air for all Americans," she said.
The company has In a statement from its headquarters in Wolfsburg, Germany, the company denied its 3.0 litre engines had defeat devices.
"Volkswagen AG wishes to emphasise that no software has been installed in the 3-litre V6 diesel power units to alter emissions characteristics in a forbidden manner," it said.
"Volkswagen will cooperate fully with the EPA [to] clarify this matter in its entirety."
The expansion of the scandal spelled further damage to Volkswagen.
Already one chief executive of the company, Martin Winterkorn, has lost his job, and shares of the giant have lost nearly one-third of their value since the scandal erupted.
The new US notice of violation, for the larger-engined cars, could weigh on Winterkorn's replacement, Matthias Mueller, who was elevated from running VW's Porsche subsidiary. At the time of his promotion, Porsche vehicles were not known to have the defeat devices.
From the EPA alone, the company is facing a potential US$18 billion in fines, but there are also a number of owner lawsuits against the company.
The new notice covers about 10,000 mostly luxury cars already sold in the United States, and an unknown number still unsold.
The software makes the engines run according to US standards when emissions testing is ongoing.
"At exactly one second" after the emission test ends, Giles said, the software switches into standard-drive mode in which poisonous nitrogen oxide emissions rise to up to nine times the EPA standard.
Volkswagen is now in violation of two provisions of the US Clean Air Act, in making and selling cars that have defeat devices and that do not meet US emissions standards.