Diesel emmisions
Discussion
As we are being told its not the CO2 that is the problem with diesels, its the NO2 if I have got this right? And the particles?
So for a short list of cars up to 3 years old where can I get his information?
All very well to tell us all that diesels are polluting the environment but some must be better than others so where is the information?
So for a short list of cars up to 3 years old where can I get his information?
All very well to tell us all that diesels are polluting the environment but some must be better than others so where is the information?
A euro 6 diesel really isn't that bad, the E6 standard is very strict on NOx/Particulate.
Euro 5, these have a somewhat higher NOx output but also come with low particulate
Euro 4, again more NOx, more particulates but still very heavily regulated
Euro 3 and older have unregulated levels of particulates, and higher NOx outputs, particularly late models.
The problem we are currently having with diesels is that the old ones are very reliable, and over the last 5-10 years standards have tightened dramatically for them. So they're are far too many 'old' examples still on the road from before they where stricted regulated. This is less of an issue with fleet vehicles as old lorries are rather rare due to the kinds of workloads these vehicles tend to do.
Euro 5, these have a somewhat higher NOx output but also come with low particulate
Euro 4, again more NOx, more particulates but still very heavily regulated
Euro 3 and older have unregulated levels of particulates, and higher NOx outputs, particularly late models.
The problem we are currently having with diesels is that the old ones are very reliable, and over the last 5-10 years standards have tightened dramatically for them. So they're are far too many 'old' examples still on the road from before they where stricted regulated. This is less of an issue with fleet vehicles as old lorries are rather rare due to the kinds of workloads these vehicles tend to do.
The big problem is that diesels are effectively NOx production machines...
A petrol engine always runs - or at least should run
at close to the ideal fuel/air ratio, whereas a diesel is usually running effectively very lean.
The diesel has to have a reasonable amount of air in the cylinder to compress, or it won't be hot enough to ignite the injected fuel. This means that there is usually a lot of surplus oxygen left after the fuel has been burnt, and it naturally tries to combine with the nitrogen in the hot exhaust gases, producing nasties.
And NOx is a real pig to get rid of, hence the bottles of concentrated pee in Euro 6 diesels to try and react with it...
I suspect that if the engineers were left to get on with it, something could be sorted out to resolve the problem, but it would add weight, complexity, and cost, and neither the bean-counters or the paying public would be very happy with that last problem!
A petrol engine always runs - or at least should run
at close to the ideal fuel/air ratio, whereas a diesel is usually running effectively very lean.The diesel has to have a reasonable amount of air in the cylinder to compress, or it won't be hot enough to ignite the injected fuel. This means that there is usually a lot of surplus oxygen left after the fuel has been burnt, and it naturally tries to combine with the nitrogen in the hot exhaust gases, producing nasties.
And NOx is a real pig to get rid of, hence the bottles of concentrated pee in Euro 6 diesels to try and react with it...
I suspect that if the engineers were left to get on with it, something could be sorted out to resolve the problem, but it would add weight, complexity, and cost, and neither the bean-counters or the paying public would be very happy with that last problem!
Do we really need yet another thread.
If people want to believe/put undue significance on scary pictures and misinformation from politicians/propaganda groups like above, then more fool them.
Emissions from private cars are a minor contribution to already very safe air quality.
Ban all cars overnight and you wouldn't notice/measure the difference - this has been proven in cities that have controlled cars and seen no improvement.
And the fact the worst air quality measured in London recently coincided with low traffic volumes on a Sunday.
If people want to believe/put undue significance on scary pictures and misinformation from politicians/propaganda groups like above, then more fool them.
Emissions from private cars are a minor contribution to already very safe air quality.
Ban all cars overnight and you wouldn't notice/measure the difference - this has been proven in cities that have controlled cars and seen no improvement.
And the fact the worst air quality measured in London recently coincided with low traffic volumes on a Sunday.
t again..Gojira said:
The big problem is that diesels are effectively NOx production machines...
A petrol engine always runs - or at least should run at close to the ideal fuel/air ratio, whereas a diesel is usually running effectively very lean.
The diesel has to have a reasonable amount of air in the cylinder to compress, or it won't be hot enough to ignite the injected fuel. This means that there is usually a lot of surplus oxygen left after the fuel has been burnt, and it naturally tries to combine with the nitrogen in the hot exhaust gases, producing nasties.
And NOx is a real pig to get rid of, hence the bottles of concentrated pee in Euro 6 diesels to try and react with it...
I suspect that if the engineers were left to get on with it, something could be sorted out to resolve the problem, but it would add weight, complexity, and cost, and neither the bean-counters or the paying public would be very happy with that last problem!
The AdPlus - concentrated pee A petrol engine always runs - or at least should run
at close to the ideal fuel/air ratio, whereas a diesel is usually running effectively very lean.The diesel has to have a reasonable amount of air in the cylinder to compress, or it won't be hot enough to ignite the injected fuel. This means that there is usually a lot of surplus oxygen left after the fuel has been burnt, and it naturally tries to combine with the nitrogen in the hot exhaust gases, producing nasties.
And NOx is a real pig to get rid of, hence the bottles of concentrated pee in Euro 6 diesels to try and react with it...
I suspect that if the engineers were left to get on with it, something could be sorted out to resolve the problem, but it would add weight, complexity, and cost, and neither the bean-counters or the paying public would be very happy with that last problem!
- is essentially concentrated Nitrogen, whose presence in the combustion chamber means there is less Oxygen (well, less of a surplus ) at the point of combustion and so the engine is running less lean. And so the combustion temperature is lower, meaning there is less NOx in the exhaust gases; higher combustion temps mean more NOx (more "nasties" , as you refer to them) in the exhaust gases...And - magically - there's yer engineers' solution to resolve the problem (though it adds weight, complexity and cost
).EGR (exhaust gas recirculation) - which is pumping some of the exhaust gases back through the engine to reduce the amount of Oxygen in the combustion chamber thus reducing combustion temps - has been used (still is?) as well; but some manufacturers found that their turbo seals were a bit fragile when the system failed (read on) and their diesel engines revved past the red line uncontrollably then blew up due to ingesting their own oil fumes when the turbo oil seals failed on the inlet side and - in effect - the engines had a full fat feed of oil akin to wading through a box of pork scratchings with a vat of beer (not healthy
).EGR valves are prone to sticking in position - often closed, allowing the exhaust gases to pass them by rather than some being recycled; some makes are more known for this than others, but one manufacturer's petrol engines are prone to this with no apparent effect to the driver other than rough running & a yellow light on the dashboard while a particular diesel engine from another manufacturer was especially prone to this - no exhaust gas recycling meant significantly hotter combustion temps, the exhaust gases from which fried the turbo which meant deteriorated oil seals and the unfortunate outcome in the previous paragraph...
I just wish that people understood the fine details of petrol and diesel exhaust emissions and the combustion processes behind them
.aw51 121565 said:
The AdPlus - concentrated pee - is essentially concentrated Nitrogen, whose presence in the combustion chamber means there is less Oxygen (well, less of a surplus ) at the point of combustion and so the engine is running less lean. And so the combustion temperature is lower, meaning there is less NOx in the exhaust gases; higher combustion temps mean more NOx (more "nasties" , as you refer to them) in the exhaust gases...
And - magically - there's yer engineers' solution to resolve the problem (though it adds weight, complexity and cost ).
EGR (exhaust gas recirculation) - which is pumping some of the exhaust gases back through the engine to reduce the amount of Oxygen in the combustion chamber thus reducing combustion temps - has been used (still is?) as well; but some manufacturers found that their turbo seals were a bit fragile when the system failed (read on) and their diesel engines revved past the red line uncontrollably then blew up due to ingesting their own oil fumes when the turbo oil seals failed on the inlet side and - in effect - the engines had a full fat feed of oil akin to wading through a box of pork scratchings with a vat of beer (not healthy ).
EGR valves are prone to sticking in position - often closed, allowing the exhaust gases to pass them by rather than some being recycled; some makes are more known for this than others, but one manufacturer's petrol engines are prone to this with no apparent effect to the driver other than rough running & a yellow light on the dashboard while a particular diesel engine from another manufacturer was especially prone to this - no exhaust gas recycling meant significantly hotter combustion temps, the exhaust gases from which fried the turbo which meant deteriorated oil seals and the unfortunate outcome in the previous paragraph...
I just wish that people understood the fine details of petrol and diesel exhaust emissions and the combustion processes behind them .
Interesting... Tell me more of this AdPlus that's injected into the combustion chamber to cool combustion temperatures and reduce oxygen, because Google has no record of it. I mean there's AdBlue (DEF) of course, but that's urea and distilled water, not nitrogen. AdBlue is also injected into the exhaust not the combustion chamber, and thus does nothing for combustion temperatures or air/fuel ratios. Its urea decomposes into ammonia and CO2 when sprayed into the exhaust stream, thus catalytically reducing NOx to nitrogen and water. As you said, people should really understand, so I'm looking forward to learning something new. - is essentially concentrated Nitrogen, whose presence in the combustion chamber means there is less Oxygen (well, less of a surplus ) at the point of combustion and so the engine is running less lean. And so the combustion temperature is lower, meaning there is less NOx in the exhaust gases; higher combustion temps mean more NOx (more "nasties" , as you refer to them) in the exhaust gases...And - magically - there's yer engineers' solution to resolve the problem (though it adds weight, complexity and cost
).EGR (exhaust gas recirculation) - which is pumping some of the exhaust gases back through the engine to reduce the amount of Oxygen in the combustion chamber thus reducing combustion temps - has been used (still is?) as well; but some manufacturers found that their turbo seals were a bit fragile when the system failed (read on) and their diesel engines revved past the red line uncontrollably then blew up due to ingesting their own oil fumes when the turbo oil seals failed on the inlet side and - in effect - the engines had a full fat feed of oil akin to wading through a box of pork scratchings with a vat of beer (not healthy
).EGR valves are prone to sticking in position - often closed, allowing the exhaust gases to pass them by rather than some being recycled; some makes are more known for this than others, but one manufacturer's petrol engines are prone to this with no apparent effect to the driver other than rough running & a yellow light on the dashboard while a particular diesel engine from another manufacturer was especially prone to this - no exhaust gas recycling meant significantly hotter combustion temps, the exhaust gases from which fried the turbo which meant deteriorated oil seals and the unfortunate outcome in the previous paragraph...
I just wish that people understood the fine details of petrol and diesel exhaust emissions and the combustion processes behind them
.
PS: I don't drive a diesel and don't really care, but your post piqued my interest.
Once diesels are taxed to high heaven they'll get straight back on CO2 so there shouldn't be anyone wanting them to ban anything, instead we should be getting on the government's case about it's lack of a proper road & transport policy, instead we've had to put up with vote winning policies that have lead us to here.
rainmakerraw said:
aw51 121565 said:
The AdPlus - concentrated pee - is essentially concentrated Nitrogen, whose presence in the combustion chamber means there is less Oxygen (well, less of a surplus ) at the point of combustion and so the engine is running less lean. And so the combustion temperature is lower, meaning there is less NOx in the exhaust gases; higher combustion temps mean more NOx (more "nasties" , as you refer to them) in the exhaust gases...
And - magically - there's yer engineers' solution to resolve the problem (though it adds weight, complexity and cost ).
EGR (exhaust gas recirculation) - which is pumping some of the exhaust gases back through the engine to reduce the amount of Oxygen in the combustion chamber thus reducing combustion temps - has been used (still is?) as well; but some manufacturers found that their turbo seals were a bit fragile when the system failed (read on) and their diesel engines revved past the red line uncontrollably then blew up due to ingesting their own oil fumes when the turbo oil seals failed on the inlet side and - in effect - the engines had a full fat feed of oil akin to wading through a box of pork scratchings with a vat of beer (not healthy ).
EGR valves are prone to sticking in position - often closed, allowing the exhaust gases to pass them by rather than some being recycled; some makes are more known for this than others, but one manufacturer's petrol engines are prone to this with no apparent effect to the driver other than rough running & a yellow light on the dashboard while a particular diesel engine from another manufacturer was especially prone to this - no exhaust gas recycling meant significantly hotter combustion temps, the exhaust gases from which fried the turbo which meant deteriorated oil seals and the unfortunate outcome in the previous paragraph...
I just wish that people understood the fine details of petrol and diesel exhaust emissions and the combustion processes behind them .
Interesting... Tell me more of this AdPlus that's injected into the combustion chamber to cool combustion temperatures and reduce oxygen, because Google has no record of it. I mean there's AdBlue (DEF) of course, but that's urea and distilled water, not nitrogen. AdBlue is also injected into the exhaust not the combustion chamber, and thus does nothing for combustion temperatures or air/fuel ratios. Its urea decomposes into ammonia and CO2 when sprayed into the exhaust stream, thus catalytically reducing NOx to nitrogen and water. As you said, people should really understand, so I'm looking forward to learning something new. - is essentially concentrated Nitrogen, whose presence in the combustion chamber means there is less Oxygen (well, less of a surplus ) at the point of combustion and so the engine is running less lean. And so the combustion temperature is lower, meaning there is less NOx in the exhaust gases; higher combustion temps mean more NOx (more "nasties" , as you refer to them) in the exhaust gases...And - magically - there's yer engineers' solution to resolve the problem (though it adds weight, complexity and cost
).EGR (exhaust gas recirculation) - which is pumping some of the exhaust gases back through the engine to reduce the amount of Oxygen in the combustion chamber thus reducing combustion temps - has been used (still is?) as well; but some manufacturers found that their turbo seals were a bit fragile when the system failed (read on) and their diesel engines revved past the red line uncontrollably then blew up due to ingesting their own oil fumes when the turbo oil seals failed on the inlet side and - in effect - the engines had a full fat feed of oil akin to wading through a box of pork scratchings with a vat of beer (not healthy
).EGR valves are prone to sticking in position - often closed, allowing the exhaust gases to pass them by rather than some being recycled; some makes are more known for this than others, but one manufacturer's petrol engines are prone to this with no apparent effect to the driver other than rough running & a yellow light on the dashboard while a particular diesel engine from another manufacturer was especially prone to this - no exhaust gas recycling meant significantly hotter combustion temps, the exhaust gases from which fried the turbo which meant deteriorated oil seals and the unfortunate outcome in the previous paragraph...
I just wish that people understood the fine details of petrol and diesel exhaust emissions and the combustion processes behind them
.PS: I don't drive a diesel and don't really care, but your post piqued my interest.
caelite said:
A euro 6 diesel really isn't that bad, the E6 standard is very strict on NOx/Particulate.
Euro 5, these have a somewhat higher NOx output but also come with low particulate
Euro 4, again more NOx, more particulates but still very heavily regulated
Euro 3 and older have unregulated levels of particulates, and higher NOx outputs, particularly late models.
The problem we are currently having with diesels is that the old ones are very reliable, and over the last 5-10 years standards have tightened dramatically for them. So they're are far too many 'old' examples still on the road from before they where stricted regulated. This is less of an issue with fleet vehicles as old lorries are rather rare due to the kinds of workloads these vehicles tend to do.
As the image below your post illustrated, the stated limits for each Euro category don't bear much relation to the actual output. Euro 5, these have a somewhat higher NOx output but also come with low particulate
Euro 4, again more NOx, more particulates but still very heavily regulated
Euro 3 and older have unregulated levels of particulates, and higher NOx outputs, particularly late models.
The problem we are currently having with diesels is that the old ones are very reliable, and over the last 5-10 years standards have tightened dramatically for them. So they're are far too many 'old' examples still on the road from before they where stricted regulated. This is less of an issue with fleet vehicles as old lorries are rather rare due to the kinds of workloads these vehicles tend to do.
aw51 121565 said:
The AdPlus - concentrated pee - is essentially concentrated Nitrogen, whose presence in the combustion chamber means there is less Oxygen (well, less of a surplus ) at the point of combustion and so the engine is running less lean. And so the combustion temperature is lower, meaning there is less NOx in the exhaust gases; higher combustion temps mean more NOx (more "nasties" , as you refer to them) in the exhaust gases...
And - magically - there's yer engineers' solution to resolve the problem (though it adds weight, complexity and cost ).
EGR (exhaust gas recirculation) - which is pumping some of the exhaust gases back through the engine to reduce the amount of Oxygen in the combustion chamber thus reducing combustion temps - has been used (still is?) as well; but some manufacturers found that their turbo seals were a bit fragile when the system failed (read on) and their diesel engines revved past the red line uncontrollably then blew up due to ingesting their own oil fumes when the turbo oil seals failed on the inlet side and - in effect - the engines had a full fat feed of oil akin to wading through a box of pork scratchings with a vat of beer (not healthy ).
EGR valves are prone to sticking in position - often closed, allowing the exhaust gases to pass them by rather than some being recycled; some makes are more known for this than others, but one manufacturer's petrol engines are prone to this with no apparent effect to the driver other than rough running & a yellow light on the dashboard while a particular diesel engine from another manufacturer was especially prone to this - no exhaust gas recycling meant significantly hotter combustion temps, the exhaust gases from which fried the turbo which meant deteriorated oil seals and the unfortunate outcome in the previous paragraph...
I just wish that people understood the fine details of petrol and diesel exhaust emissions and the combustion processes behind them .
If you put Adblue in the fuel your emmissions will be reduced to zero, because your engine won't run. - is essentially concentrated Nitrogen, whose presence in the combustion chamber means there is less Oxygen (well, less of a surplus ) at the point of combustion and so the engine is running less lean. And so the combustion temperature is lower, meaning there is less NOx in the exhaust gases; higher combustion temps mean more NOx (more "nasties" , as you refer to them) in the exhaust gases...And - magically - there's yer engineers' solution to resolve the problem (though it adds weight, complexity and cost
).EGR (exhaust gas recirculation) - which is pumping some of the exhaust gases back through the engine to reduce the amount of Oxygen in the combustion chamber thus reducing combustion temps - has been used (still is?) as well; but some manufacturers found that their turbo seals were a bit fragile when the system failed (read on) and their diesel engines revved past the red line uncontrollably then blew up due to ingesting their own oil fumes when the turbo oil seals failed on the inlet side and - in effect - the engines had a full fat feed of oil akin to wading through a box of pork scratchings with a vat of beer (not healthy
).EGR valves are prone to sticking in position - often closed, allowing the exhaust gases to pass them by rather than some being recycled; some makes are more known for this than others, but one manufacturer's petrol engines are prone to this with no apparent effect to the driver other than rough running & a yellow light on the dashboard while a particular diesel engine from another manufacturer was especially prone to this - no exhaust gas recycling meant significantly hotter combustion temps, the exhaust gases from which fried the turbo which meant deteriorated oil seals and the unfortunate outcome in the previous paragraph...
I just wish that people understood the fine details of petrol and diesel exhaust emissions and the combustion processes behind them
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