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The Dirty Truth About 'Clean Diesel' (nytimes.com)
HughPickens.com writes: Volkswagen persuaded consumers it had created a new generation of so-called clean diesel cars — until investigators discovered that phony testing concealed that its vehicles emitted up to 40 times the permitted levels of pollutants during regular use. Now Taras Grescoe writes in the NY Times public outrage over the fraud obscures the much larger issue: "clean diesel" is causing a precipitous decline in air quality for millions of city-dwellers. Monitoring sites in European cities like London, Stuttgart, Munich, Paris, Milan and Rome have reported high levels of the nitrogen oxides and particulate matter, or soot, that help to create menacing smogs. Although automakers worked hard to convince consumers that a new generation of "clean diesel" cars were far less polluting, diesel has a fatal flaw. It tends to burn dirty, particularly at low speeds and temperatures. In cities, where so much driving is stop and start, incomplete diesel combustion produces pollution that is devastating for human health.
Fortunately, Volkswagen sold only half a million of its "clean diesel" cars to the American public before the emissions scandal broke. Today, fewer than 1 percent of the passenger vehicles sold in the U.S. run on diesel fuel. Europe is now scrambling to undo the damage. In London, Mayor Boris Johnson last year called for a national program to pay some drivers to scrap their diesel vehicles. In Paris, Mayor Anne Hidalgo has gained broad support for a proposed ban on diesel cars. "Last month, the signatories of the climate deal in Paris agreed that the world has to begin a long-term shift from fossil fuels to more sustainable forms of energy," concludes Grescoe. "Recognizing "clean diesel" for the oxymoron it is would be a good place to start."
Fortunately, Volkswagen sold only half a million of its "clean diesel" cars to the American public before the emissions scandal broke. Today, fewer than 1 percent of the passenger vehicles sold in the U.S. run on diesel fuel. Europe is now scrambling to undo the damage. In London, Mayor Boris Johnson last year called for a national program to pay some drivers to scrap their diesel vehicles. In Paris, Mayor Anne Hidalgo has gained broad support for a proposed ban on diesel cars. "Last month, the signatories of the climate deal in Paris agreed that the world has to begin a long-term shift from fossil fuels to more sustainable forms of energy," concludes Grescoe. "Recognizing "clean diesel" for the oxymoron it is would be a good place to start."
My own nose is able to tell that diesel isn't particularly clean burning.
If diesels pollute mostly at low speeds and temperatures, why not make diesel hybrids, which would allow the diesel to run at peak efficiency and/or cleanliness?
This makes a great story:
But nobody ever mentions the actual level - which is pretty damn important because 40 times 1 part per thousand is a lot more significant than 40 times 1 part per trillion.
Yes VW cheated - but lets not forget that the "Clean Diesel" TDIs are MUCH cleaner than the previous generation diesel cars (TDIs included) that were on the market. Anyone who has owned both can tell you, the clean diesel TDIs don't smell, never emit black smoke and the tail pipe stays clean and doesn't fill with soot the way the old cars did.
VW broke the law and should be punished, but this isn't the BP oil spill.
... nonexistent.
Wow...hyperbole much?
True, but let's not forget that the USA is generally HUGE compared to most European countries and the USA has an overall population density which is pretty low. This is why we spend so much time in our cars, it's a long way to work and Grandma's house.
Let's also not forget that automobiles have vastly improved their emission standards and efficiency over the last few decades. I remember the yellow-brown haze which blanked LA nearly continuously in the 80's and have noticed that it's not nearly as bad anymore. So all is not lost.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
Protip: I would have modded this up if you removed the first four words.
So many good posts end up at +1 because of hyperbole or bombast. Make a good point and it stands on its own.
Well, except for the part where we're destroying huge swaths of forests /rain forests and that acidification of the ocean is killing off huge amours of the algae that would normally yum up some extra CO2
S, yes, as a matter of fact, CO2 IS a problem
The Digital Sorceress
Better off with a gas-electric hybrid. Electric motor has even more low-end torque than diesel.
Depends on the application. Diesels-electrics are used in locomotives and I think they would probably work fairly well in similar applications like in large cargo hauling trucks. I think it wouldn't make sense for a small city runabout or a family sedan but for big trucks I'm kind of surprised we haven't seen it worked on already. Diesels are actually best in steady state applications which is why they are great for trucks. Yes they are torquey but their fuel efficiency is their primary draw and that comes from operating at (relatively) constant speeds.
Your comments highlight the crux of the problem. Back in the day, inefficient (read truck like) diesel were shooting out black smoke. That particulate is large in size (10 or 100 of microns) that you actually "see". Improvements in efficiencies (both in combustion and trapping) made modern "clean engines" reduced the size of particulate to few microns. Those are much more difficult to see. Yet they are far more dangerous. Large particulate is trapped in your upper respiratory tract, the fine stuff gets deep in your lungs, often bioaccumulaating like abspestos does. You know how the stoey goes. Not because you don't see it it means it's not there... Next time stick a paper towel on the exhaust of your cold diesel and leave it there for a few minutes. Look at the color. Now you have somerhing to "see".
The OP's point is not that NOx isn't noxious, it's that it isn't persistent. The ozone created by sunlight on NOX is unstable and breaks down quickly. If we stopped pumping NOx into the atmosphere, it and its byproducts would all be gone in a matter of weeks. The same can't be said of CO2.
As well as the fact that all of humanity pays for the problems of CO2, whereas NOx just affects the rich nations pumping out all the crap in the first place.
Personally, I think there should be more emphasis on plug-in hybrids with Diesel based range extenders. Then the battery can be used around town (where the NOx is a problem), and the Diesel can be used on longer journeys where country roads don't have a NOx problem.