Volkswagen diesel scandal
11-04-15, 12:19 PM
#406
Lexus Champion
Thread Starter
Europe is realizing that now. France went as far as admitting diesel was a complete mistake.
http://www.autoblog.com/2014/12/01/f...to-ban-diesel/
http://www.autoblog.com/2014/12/01/f...to-ban-diesel/
You are right. NOx reacts in sunlight to form smog, which I know from first-hand experience is terribly discomforting and dangerous to those with respiratory problems.
Ground-level smog is much worse in the large European cities (where they have been promoting diesel cars for their low fuel consumption (and thus low CO2 emissions)) than in North America where the EPA's emission controls have concentrated on lowering NOx emissions.
But CO2 is a greenhouse gas and Europe has been worried about global warming, which is why they have concentrated on reducing CO2 (at the expense of NOx emissions) until very recently, with the introduction of the Euro 6 emissions rules.
VW's 2-litre 4-cylinder diesel engines that are being recalled were designed back when there was the great difference between European and North American emissions regulations. European regulations wanted low CO2 emissions but North American regulations were stricter, wanting much lower NOx emissions. Adding NOx controls that were not needed in Europe but needed in North America could be very expensive, especially if VW used Daimler's AdBlue SCR, so VW tried another system, the Lean NOx Trap.
The Lean NOx Trap would trap NOx but the trap would have to be purged / regenerated once it was full. One method of purging the NOx was with diesel fuel, which reacts with the trapped NOx. But this is less efficient than the AdBlue SCR and also uses additional diesel fuel.
11-04-15, 08:20 PM
#409
You are right. NOx reacts in sunlight to form smog, which I know from first-hand experience is terribly discomforting and dangerous to those with respiratory problems.
Ground-level smog is much worse in the large European cities (where they have been promoting diesel cars for their low fuel consumption (and thus low CO2 emissions)) than in North America where the EPA's emission controls have concentrated on lowering NOx emissions.
But CO2 is a greenhouse gas and Europe has been worried about global warming, which is why they have concentrated on reducing CO2 (at the expense of NOx emissions) until very recently, with the introduction of the Euro 6 emissions rules.
VW's 2-litre 4-cylinder diesel engines that are being recalled were designed back when there was the great difference between European and North American emissions regulations. European regulations wanted low CO2 emissions but North American regulations were stricter, wanting much lower NOx emissions. Adding NOx controls that were not needed in Europe but needed in North America could be very expensive, especially if VW used Daimler's AdBlue SCR, so VW tried another system, the Lean NOx Trap.
The Lean NOx Trap would trap NOx but the trap would have to be purged / regenerated once it was full. One method of purging the NOx was with diesel fuel, which reacts with the trapped NOx. But this is less efficient than the AdBlue SCR and also uses additional diesel fuel.
Ground-level smog is much worse in the large European cities (where they have been promoting diesel cars for their low fuel consumption (and thus low CO2 emissions)) than in North America where the EPA's emission controls have concentrated on lowering NOx emissions.
But CO2 is a greenhouse gas and Europe has been worried about global warming, which is why they have concentrated on reducing CO2 (at the expense of NOx emissions) until very recently, with the introduction of the Euro 6 emissions rules.
VW's 2-litre 4-cylinder diesel engines that are being recalled were designed back when there was the great difference between European and North American emissions regulations. European regulations wanted low CO2 emissions but North American regulations were stricter, wanting much lower NOx emissions. Adding NOx controls that were not needed in Europe but needed in North America could be very expensive, especially if VW used Daimler's AdBlue SCR, so VW tried another system, the Lean NOx Trap.
The Lean NOx Trap would trap NOx but the trap would have to be purged / regenerated once it was full. One method of purging the NOx was with diesel fuel, which reacts with the trapped NOx. But this is less efficient than the AdBlue SCR and also uses additional diesel fuel.
Well, Europe focused on NOx as well, but made test that can easily be circumvented as we have learned. Only reason Europe focused more on CO2 (which there is no limit for BTW, unlike for NOx) is because it is easier to do and basically they do whatever European manufacturers tell them.
Even now, after all this is happening, they actually proposed to delay new realistic testing rules until 2021, and even after that they propose to increase NOx limits by 50%. Delay to 2017 also means 100% increase in NOx limits.
So in the end, in Europe, it is all about money and manufacturers and much less about people and quality of living... while US govt cares about quality of living a lot more than about manufacturers. Completely different from perception of average European, that thinks that we are way more protected than rest of the world, especially USA:
11-04-15, 08:29 PM
#410
Get a load of this..........there's even a video commercial now on the scandal.
Volkswagen's Emissions Scandal Commercial ("The Force" parody) - YouTube
Volkswagen's Emissions Scandal Commercial ("The Force" parody) - YouTube
11-05-15, 11:27 AM
#411
Super Moderator
I must say, I don't understand the reasoning behind cheating on the 3.0V6. On the 4-banger, I get it. The cheat mode let them get away with selling an engine without an SCR mixer, urea tank/pump/injectors and all the costs associated with it. That's a huge savings and I can see why it was tempting.
But...The larger V6 already HAS all of that stuff. It wouldn't be able to make emissions without it, cheat mode or no. The consequence of cheating is that the car consumes less AdBlue/urea, and emits more NOx. But urea is cheap ($6/gallon at every AutoZone in the country, even less at truck stops), and the customer pays for it anyway. I can't see there being a huge backlash because a car consumed urea at a rate of 1000mpg instead of 1250mpg (assuming 25mpg fuel economy and using 2.5% urea instead of the advertised 2%). You're literally talking about an operating cost difference of $1.20 per thousand miles. So why take the risk?
But...The larger V6 already HAS all of that stuff. It wouldn't be able to make emissions without it, cheat mode or no. The consequence of cheating is that the car consumes less AdBlue/urea, and emits more NOx. But urea is cheap ($6/gallon at every AutoZone in the country, even less at truck stops), and the customer pays for it anyway. I can't see there being a huge backlash because a car consumed urea at a rate of 1000mpg instead of 1250mpg (assuming 25mpg fuel economy and using 2.5% urea instead of the advertised 2%). You're literally talking about an operating cost difference of $1.20 per thousand miles. So why take the risk?
Last edited by geko29; 11-05-15 at 11:41 AM.
11-05-15, 04:20 PM
#412
Lexus Champion
Maybe these engines simply cannot meet their power and emissions targets so VW chose to cheat on emissions.
11-05-15, 05:51 PM
#413
I must say, I don't understand the reasoning behind cheating on the 3.0V6. On the 4-banger, I get it. The cheat mode let them get away with selling an engine without an SCR mixer, urea tank/pump/injectors and all the costs associated with it. That's a huge savings and I can see why it was tempting.
But...The larger V6 already HAS all of that stuff. It wouldn't be able to make emissions without it, cheat mode or no. The consequence of cheating is that the car consumes less AdBlue/urea, and emits more NOx. But urea is cheap ($6/gallon at every AutoZone in the country, even less at truck stops), and the customer pays for it anyway. I can't see there being a huge backlash because a car consumed urea at a rate of 1000mpg instead of 1250mpg (assuming 25mpg fuel economy and using 2.5% urea instead of the advertised 2%). You're literally talking about an operating cost difference of $1.20 per thousand miles. So why take the risk?
But...The larger V6 already HAS all of that stuff. It wouldn't be able to make emissions without it, cheat mode or no. The consequence of cheating is that the car consumes less AdBlue/urea, and emits more NOx. But urea is cheap ($6/gallon at every AutoZone in the country, even less at truck stops), and the customer pays for it anyway. I can't see there being a huge backlash because a car consumed urea at a rate of 1000mpg instead of 1250mpg (assuming 25mpg fuel economy and using 2.5% urea instead of the advertised 2%). You're literally talking about an operating cost difference of $1.20 per thousand miles. So why take the risk?
p.s now that i think about it, 200% higher limits on NOx puts under EuroVI, puts them quite close to levels that EPA tested these VW V6 engines at. They just dont want to do anything about it, do they?
Last edited by spwolf; 11-05-15 at 05:58 PM.
11-06-15, 05:34 AM
#414
Super Moderator
The cheating on the 4-cylinder was to run the engine rich during the test cycle, which increases exhaust gas temperatures, thereby burning off the soot and breaking down the NOx in the DPF. It's essentially in the "active regeneration" cycle all the time. This also has the unwanted side effects of decreasing both fuel economy and power. This was necessary because the H2S catalyst used in this system is not anywhere near as effective as an SCR catalyst, so the DPF had do to nearly all the work, which it could only do at consistently high EGT.
But if I understand the situation on the 3.0 V6 correctly, the cheat is not to run the engine rich through the entire testing cycle--as on the smaller engine--but rather to inject more urea to further reduce NOx emissions. That's where my confusion comes in--there's minimal downside to just leaving the cheat enabled all the time. Using more urea does not decrease fuel economy or power, it just increases urea consumption.
If, in fact, the goal of the cheat was to make the engine more competitive with regards to mpg and performance, the plot failed spectacularly. The VW/Audi 3.0 puts up power and economy numbers that are nearly identical to BMW, Mercedes, and Jeep (Fiat) 3.0s:
VW Touraeg/Porsche Cayenne: 240hp/407lbft 20/29mpg
Mercedes ML350: 240hp/455lbft 20/28mpg
Jeep Grand Cherokee: 240hp/420lbft 22/30mpg
BMW X5: 255hp/413lbft 24/31mpg
11-06-15, 06:12 AM
#415
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So in the end, in Europe, it is all about money and manufacturers and much less about people and quality of living... while US govt cares about quality of living a lot more than about manufacturers. Completely different from perception of average European, that thinks that we are way more protected than rest of the world, especially USA:
My CT 200h and other hybrids pays less tax than many diesel models, ever if it is a petrol engine. So why did people start to buy diesels ? Its pretty clear I think. The diesel is cheaper to buy than any hybrid, faster and better driveability than many hybrids and less expensive to maintain.
Most governments in Europe wants to eliminiate prive cars in the cities to the maximum, no matter which fuel its powered with. More and more restrictions every year and more and more taxes for passing the city lines. Norway wants private cars to be forbidden by 2020 in major cities, only busses and trucks will be allowed, other countries have similar plans.
11-06-15, 02:24 PM
#416
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11-06-15, 02:55 PM
#417
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I dont think this will happen the way the press passed it. There will probably be restricted areas on some hours of the day or something like that. Since people live and work in the city center there must be all kind of transports. On the other hand, I have never been in Norway so I dont know how their infrastructure looks.
11-06-15, 10:09 PM
#420
As I said before, the enviromental debate ( global warming ) has to 95% been about CO2 levels, from the media, from the EU parlament and so on. The taxes has been designed to lower the CO2 levles and has nothing to do with petrol vs diesel, gas, ethanol and so on. You pay for the amounth of CO2 you vehicle produces.
My CT 200h and other hybrids pays less tax than many diesel models, ever if it is a petrol engine. So why did people start to buy diesels ? Its pretty clear I think. The diesel is cheaper to buy than any hybrid, faster and better driveability than many hybrids and less expensive to maintain.
Most governments in Europe wants to eliminiate prive cars in the cities to the maximum, no matter which fuel its powered with. More and more restrictions every year and more and more taxes for passing the city lines. Norway wants private cars to be forbidden by 2020 in major cities, only busses and trucks will be allowed, other countries have similar plans.
My CT 200h and other hybrids pays less tax than many diesel models, ever if it is a petrol engine. So why did people start to buy diesels ? Its pretty clear I think. The diesel is cheaper to buy than any hybrid, faster and better driveability than many hybrids and less expensive to maintain.
Most governments in Europe wants to eliminiate prive cars in the cities to the maximum, no matter which fuel its powered with. More and more restrictions every year and more and more taxes for passing the city lines. Norway wants private cars to be forbidden by 2020 in major cities, only busses and trucks will be allowed, other countries have similar plans.
As to why diesels gained popularity, it has nothing to do with hybrids... it was due to low fuel consumption, high performance vs NA petrols and much lower fuel price in most of the Europe. It is an awesome concept if Euro emission laws were respected....
It has nothing to do with hybrids at all, nor where they available at the time diesels got popular... heck, they are not even available now in Europe, not in the same sense anyway.
As to low maintenance, i find that completely absurd notion - they are on other side of spectrum compared to NA petrols or even worse to hybrids.t
But again, none of that would matter if EU enforced its own emissions laws which would simply forbid most of current diesels, not tax them more but forbid completely. Same goes for letting germans do without dpf on petrols with turbos, once again complete disregard for health of their citizens in the name of corporate greed.
but hey, problem is evil facebook spying on us, lets start million comities to work on that and in the meantime raise our NOx limits to 6x higher than USAs .. who cares if Paris has to shutdown traffic every few days due to unbreathable air, it is facebook thats the problem.