6 ms·

The Dirty Truth About 'Clean Diesel'

44 points by kdazzle 11y ago

revelation 11y ago
This article is missing the forest for tiny NOx colored trees. Sure, there is an indirect health problem with pollution, but there is also a much more direct health problem: cars causing fatal accidents. The best way is hence to fix the problem at the root: personal cars do not belong in cities, and cars do not belong in pedestrian areas.
- akamaka 11y ago
  Vehicle emissions cause 53,000 premature deaths in the USA every year: http://news.mit.edu/2013/study-air-pollution-causes-200000-early-deaths-each-year-in-the-us-0829 http://news.mit.edu/2013/study-air-pollution-causes-200000-e... I'd be happier to fix both problems at once, but fixing just one would go a long way.
  - revelation 11y ago
    I've expanded on this in the other child comment, but of course banning diesel cars doesn't solve the pollution issues. There is no healthy threshold for particulate concentration and other pollution, even if safety standards want to create this illusion. It's a continuous world, after all.
  - deleted 11y ago
    [deleted]
- DanBC 11y ago
  Air pollution probably kills more people in the UK than road traffic accidents. Deaths in all road user groups is about 2,000 per year in the UK. https://www.gov.uk/government/publications/annual-road-fatalities https://www.gov.uk/government/publications/annual-road-fatal... Estimates for deaths caused by air pollution are usually stated as being about 30,000 per year, but that number could be much higher. http://www.theguardian.com/environment/2015/apr/02/air-pollution-may-cause-more-uk-deaths-than-previously-thought-say-scientists http://www.theguardian.com/environment/2015/apr/02/air-pollu...
  - revelation 11y ago
    This is where it gets difficult, as you can't directly compare these numbers. Yes, air pollution presumably causes a bunch of premature deaths, but clearly air pollution can not directly kill you. In the meantime, road traffic accidents is one, if not the biggest factor in the death of otherwise totally healthy people like teenagers, who we would easily expect to live another 40 years. In any case, the magnitude of the problem doesn't exactly matter, as banning diesel cars doesn't solve the pollution deaths. Normal gasoline cars have the same pollution problems, if only on a somewhat lesser scale, particularly when used for short distances as customary in the city. As such, yes, we still have to get rid of cars in cities to fix this.
    - DanBC 11y ago
      > but clearly air pollution can not directly kill you. People die from pollution induced asthma attack. That's pretty direct.
    - ars 11y ago
      > Normal gasoline cars have the same pollution problems, if only on a somewhat lesser scale That's not in the slightest true. A well running gasoline car produces so few pollutants that some actually produce exhaust that is cleaner than the air that entered it. No diesel can claim that.
blacksmith_tb 11y ago
The interesting thing about NOx and soot pollution is that it remains a local problem, unlike the (higher) CO2 emissions from gas engines, which are just a contribution to global climate change. In that sense, I'd say it would almost be preferable to require all passenger vehicles be diesel - people could see quickly why they should drive less... Many diesel owners in the US (myself included) run varying amounts of biodiesel in their engines, which produce slightly more NOx (generally), but less particulates.
- justincormack 11y ago
  Unfortunately drivers dont mind killing people with their emissions it turns out.
  - junto 11y ago
    People generally don't mind doing things that slowly kill other people or themselves for that matter. Smokers are a prime example. If the effect was immediate and those 9000 odd people just dropped to the ground dead as you drive past them, we would see a more direct reaction.
- Gibbon1 11y ago
  What is interesting to me is how absolutely low emissions are for hybrid cars. Not idea why but the NOX emissions are about 5 to 10 times less.
aurhum 11y ago
Some of the sources used in this article are not at all of the quality I have come to expect from the NY Times. Sources like the Daily Mail and "www.searchautoparts.com".
mschuster91 11y ago
Why does everyone concentrate on fucking cars? Cars are not the problem, the 15 biggest ships cause more pollution than ALL cars worldwide ([0]). The problems are ships (which burn stuff that's essentially waste and generally have no form of emissions treatments [1]), locomotives (these burn diesel, but again, the vast fleet of old diesel locos doesn't carry any adequate filters [2]), wood furnaces (in poor countries, where anything that burns is used to heat and cook [3]), and factories where no money is available to get their emissions under control ([3]). Also, to clarify, I'm not after greenhouse gases, but after the stuff that actually kills people. Greenhouse emissions are nasty but as others have noted, agriculture is to blame here and not cars or anything else. [0]: http://www.gizmag.com/shipping-pollution/11526/ http://www.gizmag.com/shipping-pollution/11526/ [1]: see https://en.wikipedia.org/wiki/Fuel_oil#Environmental_issues https://en.wikipedia.org/wiki/Fuel_oil#Environmental_issues [2]: http://www.russfrei-fuers-klima.de/themen/schienenverkehr/ http://www.russfrei-fuers-klima.de/themen/schienenverkehr/ (german unfortunately) [3]: https://en.wikipedia.org/wiki/2013_Eastern_China_smog#Causes https://en.wikipedia.org/wiki/2013_Eastern_China_smog#Causes (though I have to admit, it's coal, not wood, but the result is the same)
- melling 11y ago
  The article states that cars are a health problem. No one said that we should only address cars and ignore the other problems. "Recently, officials in Milan temporarily barred cars from the city; in Rome, too, persistent smog has forced the authorities to limit the use of private vehicles. Back in March, Paris was enveloped in a gray cloud of choking fumes that obscured the Eiffel Tower for hours and briefly earned the French capital the title of the world’s most polluted city, beating out even Beijing. An air quality expert in Britain reported that much of it was “stale diesel” from traffic emissions generated in European cities."
- akamaka 11y ago
  Proximity matters. Kids living close to highways are more likely to get asthma. That being said, only half of the risk is linked to nearby highways, and regional pollution matters too. But you're just making yourself sound like a doofus by saying "cars are not the problem".
venti 11y ago
If you want to know exactly what Volkswagen did in their software for the emission control unit, I recommend this talk from last week's Chaos Communication Congress: https://www.youtube.com/watch?v=xZSU1FPDiao https://www.youtube.com/watch?v=xZSU1FPDiao
mulle_nat 11y ago
Article is low on numbers "An air quality expert in Britain reported that much of it was “stale diesel” from traffic emissions generated in European cities." how much is "much of it" ? and big on personal observation like "As anybody who has seen the black smoke spewing out of the pipes of a big rig as it changes gears can testify, diesel has a fatal flaw." IMO a fluff piece.
CodeWriter23 11y ago
There's either some bias or flat out ignorance with this author. I'll start with: > In other words, a driver who steps on the accelerator of a diesel car may be filling the lungs of nearby pedestrians, cyclists, infants in strollers and other drivers with potentially deadly particulate matter. Driving a diesel car is nothing like driving a gasoline car. In a gasoline car, when you "step on the accelerator" you follow the horsepower curve, revving the engine to 5000-5500 (perhaps higher) RPMs before shifting. This is because the torque curve in a typical gasoline vehicle follows the horsepower curve until you get close to the red line, typically 6500-7000 in modern cars. In a diesel passenger car (using a VW TDI as a reference) the torque develops early, peaking at about 2000-3000 RPM, then falls as you go past 3000. So if you want to get going fast in a TDI, you keep the shifting going on at around 3000. With the way the DSG and ECU work in a TDI, that means running at about 1/3-1/2 throttle. Definitely not "stepping on it". Also note the red line on a TDI is 5000 RPM. As a side note, the TDI ECU's algorithm for detecting faulty inputs imposes about a 1.5 second delay on actually opening the throttle if you floor it from a dead stop. It's very counterintuitive if you need quick acceleration, you have to give about 1/4 throttle, then slowly increase as the car starts moving. Again, if you want to go fast, the car actually incentivizes NOT stepping on it. Second, and this is the one that everyone seems to fail to notice. The TDI passes emissions when the bypass mode is disabled, putting the ECU into normal mode. What normal mode means is the car more frequently cycles the Diesel Particulate Filter (DPF), which reduces NOx emissions by accumulating soot in the DPF then burning it by passing unburned fuel through the engine 1 out of every 4 cycles while the system is in a DPF cycle. The unspent fuel lands on the soot, then the heat from the following combustion cycle ignites it and dumps mostly ash/greatly reduced NOx down the tailpipe. There are of course performance and fuel efficiency issues with normal mode. With proper tuning of the software it should be able to both meet emissions standards without sacrificing too much in the drivability department. A decrease in mileage is inevitable though. VWs mistake in all this was failing to accept a 28/38 MPG (or 27/37) rating, and insisting on 30/40 MPG (which likely came at the behest of VW Marketing). Had they been willing to accept slightly lower MPG numbers, they would have been in compliance with the law. To me, all the kerfuffle seems a little overblown. I don't give VW a free pass for breaking the law, they need to be held accountable. But this whole idea that diesel is doomed seems very off kilter to me. Diesel produces fewer greenhouse gases, converts hydrocarbons to kinetic energy most efficiently of all internal combustion engines, has fewer emissions from ancillary chemicals than gasoline like acetone and toluene (both unregulated at present). It truly is the way forward until we can retool the worldwide vehicle fleet to be driven by electricity (30 years minimum if we start right now). When I look at this anti-diesel campaign, I look at it through the lens of the Saudi's fear not of peak oil, but of peak demand. Diesel threatens to lower the plateau of peak demand. http://www.bloomberg.com/news/articles/2015-04-12/saudi-arabia-s-plan-to-extend-the-age-of-oil http://www.bloomberg.com/news/articles/2015-04-12/saudi-arab...
foobar1962 11y ago
"The diesel engine is inherently efficient: Even a heavy sedan can get as much as 50 miles per gallon, while producing fewer carbon dioxide emissions per mile." There seems to be a common misconception about CO2 emissions from cars, evidenced in this statement. Burning hydrocarbons produces CO2 and water. The more burned, the more emitted. The efficiency of the engine (and vehicle in total) determines how much fuel is used while driving. More efficient = less emissions. Diesel engines are thermodynamically more efficient by virtue of their higher combustion temperature and pressure. It's this same high temp and pressure that causes nitrous and sulphur oxide pollutants to form in the exhaust gas. Hence there is a definite trade-off between high thermodynamic efficiency, and NOx pollution. Diesels are more efficient, but less clean.
mapt 11y ago
One way or another, the author was charged with writing a hit-piece on diesel passenger cars in order to put pressure on regulation to keep them out of the US market. They did it poorly, with little factual backing. That's because they don't have much of a case. Clean diesel can be very clean. Clean gasoline engines are something we created in the 70's, 80's, and 90's; We used to have an enormous smog problem from tailpipe emissions, but we've basically solved it through regulation of what sort of fuel gets made and what sort of emissions controls are built into cars. With diesel trucks, we resolutely refused to make the corresponding changes for several decades; It's going to take 20+ years to get the truck fleet on the same footing as cars, and we only started the ULSD rollout about 10 years ago; we've only just begun major emissions level requirements in 2015 vehicles. The trucks you and I grew up around have no attempt to control emissions whatsoever, due to the power of US industry lobbyists. There is very little comparison to the clean diesels that are now a well-developed, highly regulated chunk of the EU passenger car market. The diesel emissions scandal was about a deliberate conspiracy within one manufacturer, wherein software was written to turn off major emissions controls in order to gain a very small mileage advantage, and then turn them back on to pass emissions testing. It has no relevance whatsoever to the practicality of clean diesel engines.

44 points by kdazzle 11y ago

This article is missing the forest for tiny NOx colored trees. Sure, there is an indirect health problem with pollution, but there is also a much more direct health problem: cars causing fatal accidents. The best way is hence to fix the problem at the root: personal cars do not belong in cities, and cars do not belong in pedestrian areas.

akamaka 11y ago
Vehicle emissions cause 53,000 premature deaths in the USA every year: http://news.mit.edu/2013/study-air-pollution-causes-200000-early-deaths-each-year-in-the-us-0829 http://news.mit.edu/2013/study-air-pollution-causes-200000-e... I'd be happier to fix both problems at once, but fixing just one would go a long way.
- revelation 11y ago
  I've expanded on this in the other child comment, but of course banning diesel cars doesn't solve the pollution issues. There is no healthy threshold for particulate concentration and other pollution, even if safety standards want to create this illusion. It's a continuous world, after all.
- deleted 11y ago
  [deleted]
DanBC 11y ago
Air pollution probably kills more people in the UK than road traffic accidents. Deaths in all road user groups is about 2,000 per year in the UK. https://www.gov.uk/government/publications/annual-road-fatalities https://www.gov.uk/government/publications/annual-road-fatal... Estimates for deaths caused by air pollution are usually stated as being about 30,000 per year, but that number could be much higher. http://www.theguardian.com/environment/2015/apr/02/air-pollution-may-cause-more-uk-deaths-than-previously-thought-say-scientists http://www.theguardian.com/environment/2015/apr/02/air-pollu...
- revelation 11y ago
  This is where it gets difficult, as you can't directly compare these numbers. Yes, air pollution presumably causes a bunch of premature deaths, but clearly air pollution can not directly kill you. In the meantime, road traffic accidents is one, if not the biggest factor in the death of otherwise totally healthy people like teenagers, who we would easily expect to live another 40 years. In any case, the magnitude of the problem doesn't exactly matter, as banning diesel cars doesn't solve the pollution deaths. Normal gasoline cars have the same pollution problems, if only on a somewhat lesser scale, particularly when used for short distances as customary in the city. As such, yes, we still have to get rid of cars in cities to fix this.
  - DanBC 11y ago
    > but clearly air pollution can not directly kill you. People die from pollution induced asthma attack. That's pretty direct.
  - ars 11y ago
    > Normal gasoline cars have the same pollution problems, if only on a somewhat lesser scale That's not in the slightest true. A well running gasoline car produces so few pollutants that some actually produce exhaust that is cleaner than the air that entered it. No diesel can claim that.

blacksmith_tb 11y ago

The interesting thing about NOx and soot pollution is that it remains a local problem, unlike the (higher) CO2 emissions from gas engines, which are just a contribution to global climate change. In that sense, I'd say it would almost be preferable to require all passenger vehicles be diesel - people could see quickly why they should drive less... Many diesel owners in the US (myself included) run varying amounts of biodiesel in their engines, which produce slightly more NOx (generally), but less particulates.

justincormack 11y ago
Unfortunately drivers dont mind killing people with their emissions it turns out.
- junto 11y ago
  People generally don't mind doing things that slowly kill other people or themselves for that matter. Smokers are a prime example. If the effect was immediate and those 9000 odd people just dropped to the ground dead as you drive past them, we would see a more direct reaction.
Gibbon1 11y ago
What is interesting to me is how absolutely low emissions are for hybrid cars. Not idea why but the NOX emissions are about 5 to 10 times less.

aurhum 11y ago

Some of the sources used in this article are not at all of the quality I have come to expect from the NY Times. Sources like the Daily Mail and "www.searchautoparts.com".

mschuster91 11y ago

Why does everyone concentrate on fucking cars? Cars are not the problem, the 15 biggest ships cause more pollution than ALL cars worldwide ([0]). The problems are ships (which burn stuff that's essentially waste and generally have no form of emissions treatments [1]), locomotives (these burn diesel, but again, the vast fleet of old diesel locos doesn't carry any adequate filters [2]), wood furnaces (in poor countries, where anything that burns is used to heat and cook [3]), and factories where no money is available to get their emissions under control ([3]). Also, to clarify, I'm not after greenhouse gases, but after the stuff that actually kills people. Greenhouse emissions are nasty but as others have noted, agriculture is to blame here and not cars or anything else. [0]: http://www.gizmag.com/shipping-pollution/11526/ http://www.gizmag.com/shipping-pollution/11526/ [1]: see https://en.wikipedia.org/wiki/Fuel_oil#Environmental_issues https://en.wikipedia.org/wiki/Fuel_oil#Environmental_issues [2]: http://www.russfrei-fuers-klima.de/themen/schienenverkehr/ http://www.russfrei-fuers-klima.de/themen/schienenverkehr/ (german unfortunately) [3]: https://en.wikipedia.org/wiki/2013_Eastern_China_smog#Causes https://en.wikipedia.org/wiki/2013_Eastern_China_smog#Causes (though I have to admit, it's coal, not wood, but the result is the same)

melling 11y ago
The article states that cars are a health problem. No one said that we should only address cars and ignore the other problems. "Recently, officials in Milan temporarily barred cars from the city; in Rome, too, persistent smog has forced the authorities to limit the use of private vehicles. Back in March, Paris was enveloped in a gray cloud of choking fumes that obscured the Eiffel Tower for hours and briefly earned the French capital the title of the world’s most polluted city, beating out even Beijing. An air quality expert in Britain reported that much of it was “stale diesel” from traffic emissions generated in European cities."
akamaka 11y ago
Proximity matters. Kids living close to highways are more likely to get asthma. That being said, only half of the risk is linked to nearby highways, and regional pollution matters too. But you're just making yourself sound like a doofus by saying "cars are not the problem".

venti 11y ago

If you want to know exactly what Volkswagen did in their software for the emission control unit, I recommend this talk from last week's Chaos Communication Congress: https://www.youtube.com/watch?v=xZSU1FPDiao https://www.youtube.com/watch?v=xZSU1FPDiao

mulle_nat 11y ago

Article is low on numbers "An air quality expert in Britain reported that much of it was “stale diesel” from traffic emissions generated in European cities." how much is "much of it" ? and big on personal observation like "As anybody who has seen the black smoke spewing out of the pipes of a big rig as it changes gears can testify, diesel has a fatal flaw." IMO a fluff piece.

CodeWriter23 11y ago

There's either some bias or flat out ignorance with this author. I'll start with: > In other words, a driver who steps on the accelerator of a diesel car may be filling the lungs of nearby pedestrians, cyclists, infants in strollers and other drivers with potentially deadly particulate matter. Driving a diesel car is nothing like driving a gasoline car. In a gasoline car, when you "step on the accelerator" you follow the horsepower curve, revving the engine to 5000-5500 (perhaps higher) RPMs before shifting. This is because the torque curve in a typical gasoline vehicle follows the horsepower curve until you get close to the red line, typically 6500-7000 in modern cars. In a diesel passenger car (using a VW TDI as a reference) the torque develops early, peaking at about 2000-3000 RPM, then falls as you go past 3000. So if you want to get going fast in a TDI, you keep the shifting going on at around 3000. With the way the DSG and ECU work in a TDI, that means running at about 1/3-1/2 throttle. Definitely not "stepping on it". Also note the red line on a TDI is 5000 RPM. As a side note, the TDI ECU's algorithm for detecting faulty inputs imposes about a 1.5 second delay on actually opening the throttle if you floor it from a dead stop. It's very counterintuitive if you need quick acceleration, you have to give about 1/4 throttle, then slowly increase as the car starts moving. Again, if you want to go fast, the car actually incentivizes NOT stepping on it. Second, and this is the one that everyone seems to fail to notice. The TDI passes emissions when the bypass mode is disabled, putting the ECU into normal mode. What normal mode means is the car more frequently cycles the Diesel Particulate Filter (DPF), which reduces NOx emissions by accumulating soot in the DPF then burning it by passing unburned fuel through the engine 1 out of every 4 cycles while the system is in a DPF cycle. The unspent fuel lands on the soot, then the heat from the following combustion cycle ignites it and dumps mostly ash/greatly reduced NOx down the tailpipe. There are of course performance and fuel efficiency issues with normal mode. With proper tuning of the software it should be able to both meet emissions standards without sacrificing too much in the drivability department. A decrease in mileage is inevitable though. VWs mistake in all this was failing to accept a 28/38 MPG (or 27/37) rating, and insisting on 30/40 MPG (which likely came at the behest of VW Marketing). Had they been willing to accept slightly lower MPG numbers, they would have been in compliance with the law. To me, all the kerfuffle seems a little overblown. I don't give VW a free pass for breaking the law, they need to be held accountable. But this whole idea that diesel is doomed seems very off kilter to me. Diesel produces fewer greenhouse gases, converts hydrocarbons to kinetic energy most efficiently of all internal combustion engines, has fewer emissions from ancillary chemicals than gasoline like acetone and toluene (both unregulated at present). It truly is the way forward until we can retool the worldwide vehicle fleet to be driven by electricity (30 years minimum if we start right now). When I look at this anti-diesel campaign, I look at it through the lens of the Saudi's fear not of peak oil, but of peak demand. Diesel threatens to lower the plateau of peak demand. http://www.bloomberg.com/news/articles/2015-04-12/saudi-arabia-s-plan-to-extend-the-age-of-oil http://www.bloomberg.com/news/articles/2015-04-12/saudi-arab...

foobar1962 11y ago

"The diesel engine is inherently efficient: Even a heavy sedan can get as much as 50 miles per gallon, while producing fewer carbon dioxide emissions per mile." There seems to be a common misconception about CO2 emissions from cars, evidenced in this statement. Burning hydrocarbons produces CO2 and water. The more burned, the more emitted. The efficiency of the engine (and vehicle in total) determines how much fuel is used while driving. More efficient = less emissions. Diesel engines are thermodynamically more efficient by virtue of their higher combustion temperature and pressure. It's this same high temp and pressure that causes nitrous and sulphur oxide pollutants to form in the exhaust gas. Hence there is a definite trade-off between high thermodynamic efficiency, and NOx pollution. Diesels are more efficient, but less clean.

mapt 11y ago

One way or another, the author was charged with writing a hit-piece on diesel passenger cars in order to put pressure on regulation to keep them out of the US market. They did it poorly, with little factual backing. That's because they don't have much of a case. Clean diesel can be very clean. Clean gasoline engines are something we created in the 70's, 80's, and 90's; We used to have an enormous smog problem from tailpipe emissions, but we've basically solved it through regulation of what sort of fuel gets made and what sort of emissions controls are built into cars. With diesel trucks, we resolutely refused to make the corresponding changes for several decades; It's going to take 20+ years to get the truck fleet on the same footing as cars, and we only started the ULSD rollout about 10 years ago; we've only just begun major emissions level requirements in 2015 vehicles. The trucks you and I grew up around have no attempt to control emissions whatsoever, due to the power of US industry lobbyists. There is very little comparison to the clean diesels that are now a well-developed, highly regulated chunk of the EU passenger car market. The diesel emissions scandal was about a deliberate conspiracy within one manufacturer, wherein software was written to turn off major emissions controls in order to gain a very small mileage advantage, and then turn them back on to pass emissions testing. It has no relevance whatsoever to the practicality of clean diesel engines.