VAG group facing possible $18 billion fine ??

From what I can gather it seems to only affect those cars that use the AdBlue dosing additive that is used to reduce emissions. It seems that if the ECU sees a certain pattern in driving behavior it cranks up the AdBlue dosing pump to put a lot more in thus reducing emissions. However if it ran at this rate in normal driving the AdBlue would need to be filled a lot more often. So that would cost the user more money in running costs.

http://jalopnik.com/your-guide-to-dieselgate-volkswagens-diesel-cheating-c-1731857018

Karl.