In message , at 14:19:43 on Tue, 29 Sep
2015, Adrian remarked:

There was speculation that VW cheating the tests allowed them to remove
the AdBlue system from their 2-litre range hence reducing unit cost.

Small problem...

There's talk of "40x" the permitted NOx.

For Euro V (which these engines are), NOx max is .18g/km. For Euro VI
(which the AdBlue replacements are), NOx max is 0.05g/km.

I think that's 40x one of the common US limits of 0.031, and perhaps the
"cheat" is so good that it reduces the NOx to 1/40th while being tested.
--
Roland Perry