New US research seems to show that Volkswagen attempted to thwart checks on more models than originally thought. But the carmaker has denied claims it included emissions-check "defeat devices" rules in larger diesels.
The German automaker issued a swift denial on Monday after US regulators reported that Volkswagen cars with larger diesel engines were also found to have contained software aimed at skirting tests to comply with pollution rules in the United States.
The alleged violations cover models including the 2014 Touareg, 2015 Porsche Cayenne and the 2016 Audi A6 Quattro, A7 Quattro, A8 and Q5.
"Volkswagen underlines that no program has been installed in its V6 3-liter diesel engines" that would "inappropriately modify" the results of anti-pollution tests, the company claimed in a statement released late Monday.
On Monday, officials from the Environmental Protection Agency (EPA) indicated that the German carmaker had installed its cheating software in big-engine vehicles from the model years 2014 to 2016. Reuters reported that Porsche cars also contained software to cheat emission tests, alongside certain VW and Audi models.
"When the vehicle senses that it is undergoing a federal emissions test procedure, it operates in a low NOx (nitrogen oxides) temperature conditioning mode," the EPA reported after tests. "Under that mode, the vehicle meets emission standards. At exactly one second after the completion of the initial phases of the standard test procedure, the vehicle immediately changes a number of operating parameters that increase NOx emissions and indicates in the software that it is transitioning to 'normal mode,' where emissions of NOx increase up to nine times the EPA standard, depending on the vehicle and type of driving conditions."
The EPA reported that the illegal software was similar to that found in the 2009-15 models with 2-liter motors. VW officials have admitted that those cars contained software meant to cheat the tests.
The European Union has recently agreed to controversial new diesel emissions rules.
mkg/jr (EFE, AP)