Pat, in the 80's lots of motors suffered terribly when pollution gear was applied for the next year model. Again why would VW go to such (nefarious) lengths to turn it off or reduce its application when the vehicle is not on the test bed,...it is a bit naive to think it would make no difference.
See for example the discussion here about torque
http://www.wired.com/2015/09/vw-owne...fixes-diesels/
Cheers

