Euro6 diesels - better for the planet that petrols?
Discussion
Trying to summarise a theory that came to mind when posting on another thread and thinking about why we should or should not demonise modern diesels.
The key exhaust nasties (NOx and PM) on a Euro6 (c,2014+) vehicle are virtually identical, NOx is 0.06 for petrol and 0.08 on diesel (g/km), PM is the same for diesel and petrol. Both are small fractions of what they were 15 years earlier.
key thoughts:
Interested to see who may agree and who may flame me!!!
The key exhaust nasties (NOx and PM) on a Euro6 (c,2014+) vehicle are virtually identical, NOx is 0.06 for petrol and 0.08 on diesel (g/km), PM is the same for diesel and petrol. Both are small fractions of what they were 15 years earlier.
key thoughts:
- 1 - Diesels typically use a lot less fuel than equivalent petrols and as they are used by the people who tend to accumulate the larger share of the nations mileage, net CO2 across the vehicle population per mile is far lower for diesel than for petrol.
- 2 - Smaller petrol engines (think 1.5T petrols vs "equivalent" 2.0 TD) work harder per mile, more revolutions per minute, can they be expected to last as long, on average? As a large amount of pollution is attributable to a vehicles manufacturing and scrapping processes, the longer a vehicle stays in service the better.
- 3 - Petrol hybrids bring better MPG into the equation but the environmental piece regarding battery supply and disposal. Are Euro6 diesels net better as for the people doing lots of miles (and making up the biggest proportion of the national total) I would still expect a diesel to outperform a hybrid equivalent.
- 4 - As a caveat I cant see past full EV as being the long term solution subject to infrastructure and renewables being well managed.
Interested to see who may agree and who may flame me!!!
http://equaindex.com is a good source of independent real world testing.
In fairness many of the latest MY17 cars usually are close to it. But I would say looking at it diesels in many cases still fall some way from reality where petrols seem more constant with being closer to the actual ratings.
I have said before though like the OP that to class a petrol as cleaner purely from a particulates perspective is a load of bo**cks the moment it has direct injection as it will produce particulates. Sadly this is something that has until very recently been quietly disregarded.
In some way reverse mentality for a moment a diesel purely focusing on particulates will probably be less dangerous than a DI petrol. Most modern diesels really are only effective over longer distances. Particulate petrols have been increasing in recent years as well so it is not all clean as some would like.
Reality is none of the current personal transport solutions irrespective of fuel can really be "clean". Furthermore, in some part you simply move the problem to a different location (and some of that is influenced by the methods used to create say electricity, which in the UK is in someway not as "green" as other developed nations relying on other methods). Additionally in some cases the raw materials are harder to extract and more dangerous.
In fairness many of the latest MY17 cars usually are close to it. But I would say looking at it diesels in many cases still fall some way from reality where petrols seem more constant with being closer to the actual ratings.
I have said before though like the OP that to class a petrol as cleaner purely from a particulates perspective is a load of bo**cks the moment it has direct injection as it will produce particulates. Sadly this is something that has until very recently been quietly disregarded.
In some way reverse mentality for a moment a diesel purely focusing on particulates will probably be less dangerous than a DI petrol. Most modern diesels really are only effective over longer distances. Particulate petrols have been increasing in recent years as well so it is not all clean as some would like.
Reality is none of the current personal transport solutions irrespective of fuel can really be "clean". Furthermore, in some part you simply move the problem to a different location (and some of that is influenced by the methods used to create say electricity, which in the UK is in someway not as "green" as other developed nations relying on other methods). Additionally in some cases the raw materials are harder to extract and more dangerous.
Ninja59 said:
http://equaindex.com is a good source of independent real world testing.
In fairness many of the latest MY17 cars usually are close to it. But I would say looking at it diesels in many cases still fall some way from reality where petrols seem more constant with being closer to the actual ratings.
I have said before though like the OP that to class a petrol as cleaner purely from a particulates perspective is a load of bo**cks the moment it has direct injection as it will produce particulates. Sadly this is something that has until very recently been quietly disregarded.
In some way reverse mentality for a moment a diesel purely focusing on particulates will probably be less dangerous than a DI petrol. Most modern diesels really are only effective over longer distances. Particulate petrols have been increasing in recent years as well so it is not all clean as some would like.
Reality is none of the current personal transport solutions irrespective of fuel can really be "clean". Furthermore, in some part you simply move the problem to a different location (and some of that is influenced by the methods used to create say electricity, which in the UK is in someway not as "green" as other developed nations relying on other methods). Additionally in some cases the raw materials are harder to extract and more dangerous.
Thanks, good points. In fairness many of the latest MY17 cars usually are close to it. But I would say looking at it diesels in many cases still fall some way from reality where petrols seem more constant with being closer to the actual ratings.
I have said before though like the OP that to class a petrol as cleaner purely from a particulates perspective is a load of bo**cks the moment it has direct injection as it will produce particulates. Sadly this is something that has until very recently been quietly disregarded.
In some way reverse mentality for a moment a diesel purely focusing on particulates will probably be less dangerous than a DI petrol. Most modern diesels really are only effective over longer distances. Particulate petrols have been increasing in recent years as well so it is not all clean as some would like.
Reality is none of the current personal transport solutions irrespective of fuel can really be "clean". Furthermore, in some part you simply move the problem to a different location (and some of that is influenced by the methods used to create say electricity, which in the UK is in someway not as "green" as other developed nations relying on other methods). Additionally in some cases the raw materials are harder to extract and more dangerous.
Ninja59 said:
......In some way reverse mentality for a moment a diesel purely focusing on particulates will probably be less dangerous than a DI petrol. Most modern diesels really are only effective over longer distances. Particulate petrols have been increasing in recent years as well so it is not all clean as some would like....
Yes, direct injection petrols are, in many cases, dirtier than modern diesels.It's expected that within a couple of years DI petrol engines will have GPFs ('Gasoline Particle Filter') to capture the relatively large amounts of particulates that DI produces.
In fact, I'm not sure we're actually building 'cleaner' engines than a decade or more ago when port-injected, naturally aspirated petrol was common. In many real world cases those old n/a engines are not significantly less economical than the downsized+turbocharged engines which replaced them.
It's also notable that most of the remaining n/a petrols usually get very close to their claimed mpg figure in the real world, whereas their downsized replacements usually fall massively short of the claimed mpg. I think that's a consequence of the lab test spending very little time at speeds above 30mph resulting in engines being designed for pootling and not designed for prolonged high-speed running.
question said:
Euro6 diesels - better for the planet that petrols?
I don't think you can ask a question like that out of the context of so many other things:- environmental impact of manufacturing
- environmental impact of death / recycling
- environmental impact of lifetime maintenance (e.g. parts from Japan / Germany v. transported from Coventry)
- environmental impact of driving style
- environmental impact of extras chosen (e.g. leather v. other material / bamboo v. wood v. metal)
- environmental impact of how many miles will be driven
- environmental impact of distance to servicing / courtesy car provided
etc. etc.
the type of engine and emissions is only one small part of the environmental impact of a car - and ultimately probably not the most significant...
Ninja59 said:
Interesting site. I have a 2017 e class estate (e220d) which is rated at A+ in terms of air quality in that it both meets Euro6 standards for both diesel AND petrol whereas the 3.0 version only meets Euro 3 Diesel equivalent. Ron99 said:
Yes, direct injection petrols are, in many cases, dirtier than modern diesels.
It's expected that within a couple of years DI petrol engines will have GPFs ('Gasoline Particle Filter') to capture the relatively large amounts of particulates that DI produces.
In fact, I'm not sure we're actually building 'cleaner' engines than a decade or more ago when port-injected, naturally aspirated petrol was common. In many real world cases those old n/a engines are not significantly less economical than the downsized+turbocharged engines which replaced them.
It's also notable that most of the remaining n/a petrols usually get very close to their claimed mpg figure in the real world, whereas their downsized replacements usually fall massively short of the claimed mpg. I think that's a consequence of the lab test spending very little time at speeds above 30mph resulting in engines being designed for pootling and not designed for prolonged high-speed running.
Most are going to get rid of the FI engines or at least enlarge the capacity to meet the real world tests.It's expected that within a couple of years DI petrol engines will have GPFs ('Gasoline Particle Filter') to capture the relatively large amounts of particulates that DI produces.
In fact, I'm not sure we're actually building 'cleaner' engines than a decade or more ago when port-injected, naturally aspirated petrol was common. In many real world cases those old n/a engines are not significantly less economical than the downsized+turbocharged engines which replaced them.
It's also notable that most of the remaining n/a petrols usually get very close to their claimed mpg figure in the real world, whereas their downsized replacements usually fall massively short of the claimed mpg. I think that's a consequence of the lab test spending very little time at speeds above 30mph resulting in engines being designed for pootling and not designed for prolonged high-speed running.
Time is telling though that most of these engines really deliver little benefit as you say. The only extra factor for me was finding I loved the 3 cylinder 1.5 litre BMW engine which was light and sounded good in brutal honesty. It was also very chuckable with such little mass up front.
But purely focusing on MPG for a moment I found it little better than say if it was a larger engine.
Jag_NE said:
Trying to summarise a theory that came to mind when posting on another thread and thinking about why we should or should not demonise modern diesels.
The key exhaust nasties (NOx and PM) on a Euro6 (c,2014+) vehicle are virtually identical, NOx is 0.06 for petrol and 0.08 on diesel (g/km), PM is the same for diesel and petrol. Both are small fractions of what they were 15 years earlier.
The average in the real world is actually 0.5g/km for diesel for NOx.The key exhaust nasties (NOx and PM) on a Euro6 (c,2014+) vehicle are virtually identical, NOx is 0.06 for petrol and 0.08 on diesel (g/km), PM is the same for diesel and petrol. Both are small fractions of what they were 15 years earlier.
https://www.fleetnews.co.uk/news/fleet-industry-ne...
This is because the EU test cycle is useless and the manufacturers cheat. They (not all manufacturers, perhaps, but many) don't care if they are poisoning people, they just care about passing the arbitrary test.
They could make much lower emitting cars, and some do. But they don't HAVE to (yet), so they'd rather gas people to death.
The decision by a manufacturer to release cars that in the real world emit far more NOx than allowed, could be linked to a certain number of deaths (based on excess deaths as a result of pollution). So one could argue that those involved have blood on their hands
Jag_NE said:
key thoughts:
Co2 is harmless at the point of emission. Global accumulation of CO2 is harmful, but whereas NOx from UK vehicles certainly kills people, there are no deaths directly attributable to UK CO2.- 1 - Diesels typically use a lot less fuel than equivalent petrols and as they are used by the people who tend to accumulate the larger share of the nations mileage, net CO2 across the vehicle population per mile is far lower for diesel than for petrol.
Jag_NE said:
- 2 - Smaller petrol engines (think 1.5T petrols vs "equivalent" 2.0 TD) work harder per mile, more revolutions per minute, can they be expected to last as long, on average? As a large amount of pollution is attributable to a vehicles manufacturing and scrapping processes, the longer a vehicle stays in service the better.
I do however believe that petrol cars are lighter than diesel, and use less material. In a throwaway culture, it makes sense to use smaller engines, not long life ones that will be scrapped long before they have actually perished.
Jag_NE said:
- 3 - Petrol hybrids bring better MPG into the equation but the environmental piece regarding battery supply and disposal. Are Euro6 diesels net better as for the people doing lots of miles (and making up the biggest proportion of the national total) I would still expect a diesel to outperform a hybrid equivalent.
A quick Google search suggests that the energy cost of making the car is small relative to that burned by the vehicle. The impact of supply and disposal is an entirely different question, but there is no obvious reason why we shouldn't be able to properly recycle/dispose of car batteries.
Also there are diesel hybrids.
thelawnet1 said:
This is conjecture. Diesel cars have a reputation for premature failure. In reality most UK vehicles will be scrapped not because of engine failure but simply because the market value is less than the cost of repair. In other words there is an oversupply of new vehicles for economic reasons and because of high labour costs. If we lived in Romania, perhaps we could pay more regard to the real lifespan of the vehicle (as opposed to the UK - it's old and needs 4 new tyres, let's scrap it). But we don't, so this is barely relevant.
I do however believe that petrol cars are lighter than diesel, and use less material. In a throwaway culture, it makes sense to use smaller engines, not long life ones that will be scrapped long before they have actually perished.
To be fair lots of petrols now have issues similar to diesels, because of the various emissions related equipment. Furthermore, most manufacturers are now trying to use similar if not the same blocks for diesel and petrol so technically the weight saving via petrol is going down and in honesty with more alloy blocks being used the weight has reduced greatly in recent years even excluding engine size and cylinder count decreasing. I do however believe that petrol cars are lighter than diesel, and use less material. In a throwaway culture, it makes sense to use smaller engines, not long life ones that will be scrapped long before they have actually perished.
thelawnet1 said:
Jag_NE said:
Trying to summarise a theory that came to mind when posting on another thread and thinking about why we should or should not demonise modern diesels.
The key exhaust nasties (NOx and PM) on a Euro6 (c,2014+) vehicle are virtually identical, NOx is 0.06 for petrol and 0.08 on diesel (g/km), PM is the same for diesel and petrol. Both are small fractions of what they were 15 years earlier.
The average in the real world is actually 0.5g/km for diesel for NOx.The key exhaust nasties (NOx and PM) on a Euro6 (c,2014+) vehicle are virtually identical, NOx is 0.06 for petrol and 0.08 on diesel (g/km), PM is the same for diesel and petrol. Both are small fractions of what they were 15 years earlier.
https://www.fleetnews.co.uk/news/fleet-industry-ne...
This is because the EU test cycle is useless and the manufacturers cheat. They (not all manufacturers, perhaps, but many) don't care if they are poisoning people, they just care about passing the arbitrary test.
They could make much lower emitting cars, and some do. But they don't HAVE to (yet), so they'd rather gas people to death.
The decision by a manufacturer to release cars that in the real world emit far more NOx than allowed, could be linked to a certain number of deaths (based on excess deaths as a result of pollution). So one could argue that those involved have blood on their hands
Jag_NE said:
key thoughts:
Co2 is harmless at the point of emission. Global accumulation of CO2 is harmful, but whereas NOx from UK vehicles certainly kills people, there are no deaths directly attributable to UK CO2.- 1 - Diesels typically use a lot less fuel than equivalent petrols and as they are used by the people who tend to accumulate the larger share of the nations mileage, net CO2 across the vehicle population per mile is far lower for diesel than for petrol.
Jag_NE said:
- 2 - Smaller petrol engines (think 1.5T petrols vs "equivalent" 2.0 TD) work harder per mile, more revolutions per minute, can they be expected to last as long, on average? As a large amount of pollution is attributable to a vehicles manufacturing and scrapping processes, the longer a vehicle stays in service the better.
I do however believe that petrol cars are lighter than diesel, and use less material. In a throwaway culture, it makes sense to use smaller engines, not long life ones that will be scrapped long before they have actually perished.
Jag_NE said:
- 3 - Petrol hybrids bring better MPG into the equation but the environmental piece regarding battery supply and disposal. Are Euro6 diesels net better as for the people doing lots of miles (and making up the biggest proportion of the national total) I would still expect a diesel to outperform a hybrid equivalent.
A quick Google search suggests that the energy cost of making the car is small relative to that burned by the vehicle. The impact of supply and disposal is an entirely different question, but there is no obvious reason why we shouldn't be able to properly recycle/dispose of car batteries.
Also there are diesel hybrids.
To the CO2 point, because there have been no deaths attributable to rising CO2 levels at the point of emission that makes it less of an issue than NOx? I think rising sea levels and melting polar ice caps present far more catastrophic potential to mankind than NOx from Euro6 vehicles.
Diesel cars have a reputation for premature failure....this is when people buy them for inappropriate duty cycles.Euro6 DI turbo petrols are starting to carry a lot of similar hardware to diesel. They will form their own "reputation" as the vehicle population grows. Older petrols were simple while diesel was implementing all the new tech over the last 15 years.
Drawing a conclusion from a quick google search is a spot on definition of conjecture, well done!
Jag_NE said:
#3 - Petrol hybrids bring better MPG into the equation but the environmental piece regarding battery supply and disposal. Are Euro6 diesels net better as for the people doing lots of miles (and making up the biggest proportion of the national total) I would still expect a diesel to outperform a hybrid equivalent.
Last week, I drove a Outlander PHEV for 700 miles, it averaged 26MPG and needed filling up every 200 miles. This week I had a BMW 335D and averaged 39 MPG and did over 500 miles on a tankful.Some Guy said:
Last week, I drove a Outlander PHEV for 700 miles, it averaged 26MPG and needed filling up every 200 miles. This week I had a BMW 335D and averaged 39 MPG and did over 500 miles on a tankful.
That’s the sort of thing I’m thinking about. A state of the art hybrid chucking out 50% more CO2 than a rocket ship diesel....what about the icebergs? Some Guy said:
Last week, I drove a Outlander PHEV for 700 miles, it averaged 26MPG and needed filling up every 200 miles. This week I had a BMW 335D and averaged 39 MPG and did over 500 miles on a tankful.
That’s the sort of thing I’m thinking about. A state of the art hybrid chucking out 50% more CO2 than a rocket ship diesel....what about the icebergs? Gassing Station | General Gassing | Top of Page | What's New | My Stuff