What I don't understand is why folks think that lower emissions (test mode) = lower milage. Lower power certainly, but the mileage should actually improve. The reason they did this was not for fuel economy, but to make the diesels more sporty vs the typical leviathon work vehicles of yesteryear.
I mean think about it, more power = burning more gas per mile. There is a fixed amount of carbon in the fuel, so if emissions are lower you must be burning less of it (though this can also be affected by the quality of combustion; fuel air mix etc, i.e. the Turbo in TDI).
That article also has some strong biases that the author wears proudly on his sleeve. I don't know enough about emissions standards to either agree or disagree.
#stilllovemygolf though I am confused about whether any of this applies to me at all; mine might be older than the issue from some things I've read (2004). ... and it just passed it's regularly required emissions test a few weeks ago. I was surprised at the complete lack of comment about this when I took it in.