As a long time designer of electronic Diesel engine controllers, I can tell you that the reduction in emissions from Diesels during the 70's and early 80's has been phenomenal.
You will NEVER see black smoke from the stack of a properly running modern Diesel engine.
The problem now is that to get to Tier 4 emissions levels will take exotic technology that translates into big $$$ for the consumer.
The real agenda here is to kill the Diesel engine in North America.
If you actually look at pollution per MILE driven, Diesels are probably the most cost efficient, cleanest engines currently available.
That's why Europe is making so many of it's on road vehicles with Diesel engines.
I'll take your word for it. If so, then Bush needs to clean out the EPA and staff it with sensible people.
Either I have exceptional vision or there is a serious glut of improperly running diesel engines around here. The black puff on take off is standard, on high power needs (uphill in town) many times continuous.
I don't disagree with your assertion that improvements have been made. I also agree that Tier 4 will cost. Big, concerning cost, is open for debate in my humble opinion.
As for Europes standards - I'd rather rely on our home grown electronic Diesel engine controller designers ingenuity than their socialist systems. I would also be interested in knowing what their fuel sulfur requirements are (since it is at the heart of the matter).
Diesel engines are inherently more efficient that standard gasoline powered engines. For some reason that hasn't caught on in the US at the passenger vehicle level.
But I trust that you and your colleagues can make this workable. Did you hear about the diesel "bypass" systems - turn it on during testing to get low emission rating, turn it off otherwise?
I'd be interested to know more background on that if you have an info.