FRANKFURT • Germany's Volkswagen (VW) said on Tuesday an internal probe had found 800,000 more vehicles showing "inconsistencies" in carbon emissions, including the first petrol engines, as the auto giant sank deeper into a massive pollution-cheating scandal.
The company said initial estimates suggested that the latest revelation could cost it €2 billion (S$3.1 billion), but "a reliable assessment of the scale of these irregularities is not yet possible".
Separately, Porsche SE, the investment company which owns 32.4 per cent of VW's capital, said Tuesday's revelation could have a "negative impact" on its own results, although it maintained its projections for this year.
VW has once again failed in its obligation to comply with the law that protects clean air for all Americans.
MS CYNTHIA GILES, an official with the United States Environmental Protection Agency
Porsche's North American subsidiary announced it was suspending sales of its Cayenne diesel vehicles until further notice, but stressed that customers could continue to operate their crossover cars.
Among the engines affected are 1.4-, 1.6- and 2-litre motors of VW, Skoda, Audi and Seat vehicles, said a VW spokesman.
VW said it made erroneous carbon dioxide and fuel economy claims in Europe for cars beginning with the 2012 model years, as well as the 2015 and 2016 models currently on sale.
The affected cars are the Volkswagen Polo, Golf and Passat, and the Audi A1 and A3. Some Seat and Skoda cars are also involved.
At least one petrol engine is affected, the company said. Up to now, only its diesel engines had been affected.
Volkswagen admitted in September that it had fitted 11 million of its diesel vehicles with devices designed to cheat official pollution tests, revelations that have sparked global outrage and investigations across the globe.
The so-called "defeat devices" turn on pollution controls when cars are undergoing tests and off when they are back on the road, allowing them to spew out harmful levels of nitrogen oxide.
The latest issue opens up another front in the scandal engulfing the company as it relates to a different type of engine.
It also comes a day after the US authorities accused the carmaker of also fitting the nitrogen oxide defeat devices on larger 3-litre diesel vehicles - charges that VW has adamantly denied.
"I have pledged from the start that we will stop at nothing in clarifying the circumstances," VW chief executive Matthias Mueller said in a statement on Tuesday.
"The Volkswagen executive board regrets the facts established," he said of the internal probe that uncovered carbon dioxide irregularities.
In the United States, the authorities late on Monday accused VW of fitting illegal defeat devices not only on its smaller engines, but also into various six-cylinder 3-litre diesel cars, including the VW Touareg and Porsche Cayenne.
The inclusion of Porsche vehicles among those alleged to contain defeat devices could trip up Mr Mueller, who was drafted in from the luxury sports car unit to replace Mr Martin Winterkorn, who resigned at the height of the scandal.
"We have clear evidence of these additional violations," said Ms Cynthia Giles, an official with the US Environmental Protection Agency. "VW has once again failed in its obligation to comply with the law that protects clean air for all Americans."
Mr Mueller did not address the latest US allegations in his statement. But VW, the world's No. 2 carmaker by sales, swiftly denied the new US charges.
"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 in a statement.
Separately, VW notified its dealers and the transport regulators in the US and Canada that it will recall certain vehicles with 1.8-litre turbo and 2-litre petrol engines next month, according to a VW communique to dealers, obtained by Reuters.
The recall is due to the suspicion that the camshaft lobe may shear off, reducing engine and brake power, the company informed its dealers on Tuesday, after notifying the National Highway Traffic Safety Administration and Transport Canada.
AGENCE FRANCE-PRESSE, REUTERS, NEW YORK TIMES