Several engineers at Volkswagen have admitted to manipulating the carbon dioxide emissions data to pass the emission testing, according to a report from Reuters.
The engineers rigged the carbon dioxide emissions because the goal set by former CEO Martin Winterkorn were difficult to achieve.
Reuters adds that Volkswagen engineers have tampered with the tire pressure and mixed motor oil with their diesel to make them use less fuel.
The deception began in 2013 and has continued on until spring of this year.
Reuters adds that a Volkswagen spokesman said that employees have indicated the irregularities in fuel consumption data.
"Employees have indicated in an internal investigation that there were irregularities in ascertaining fuel consumption data," the spokesman said. "How this happened is subject to ongoing proceedings."
A person familiar with the matter told Reuters that the automaker is encouraging rank and file employees to cooperate with the internal investigation.
Volkswagen has promised not to sue or fire them for any misconduct.
Reuters adds that the people also said high-level managers, though, would still be held to account.
NDTV adds that Winterkorn declared at the Geneva auto show in March 2012 that the automaker plans to reduce its carbon dioxide emission by 30 percent by 2015.
Engineers, though, didn't dare to tell Winterkorn that his target would be difficult to achieve.
Business 2 Community adds that Volkswagen admitted on Tuesday that they have understated the fuel consumption and carbon dioxide emissions of about 800,000 vehicles sold in Europe.
The newest admission comes six weeks after the automaker admitted to installing a software that cheats during the emission testing of the vehicle in about 11 million vehicles worldwide.
Two people familiar with the matter told Reuters that Volkswagen's supervisory board would convene on Monday, October 9, 2015, for the first time in about a month.
The meeting, which would also be attended by CEO Mueller, would discuss the fallout from the widening scandal.
Reuters adds that the sources said the non-executive board is not expected to decide on the funding measures for the scandal.
They would be assessing the scale of the damage.
Business 2 Community adds that the cheating scandals are expected to cost Volkswagen €35 billion, or about $38 billion in fines, lawsuits, and vehicle refits.
