Why is diesel now bad news?

Why is diesel now bad news?

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Escort Si-130

Original Poster:

3,269 posts

179 months

Thursday 11th December 2014
quotequote all
One of the reasons why I am not a fan of diesel cars - petrol all the way.

http://www.bbc.co.uk/news/science-environment-3038...

The mayor of Paris wants the city to become 'semi-pedestrianised'
Continue reading the main story
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Air pollution 'public health crisis'
Call for Paris ban on diesel cars

The Mayor of Paris Anne Hidalgo wants to ban diesel cars and the pollution they bring from the streets of the French capital. But not long ago, diesel engines were thought to be environmentally friendly. What could have gone wrong?

Opinion on diesel cars has swung widely over the years.

Diesel is a more efficient fuel than petrol, but in the past diesel engines were often noisy and dirty.

Then, with growing concerns over climate change, car manufacturers were urged to produce cleaner, quieter diesel cars to capitalise on their extra fuel efficiency.

The cars were fitted with a trap to catch the particles of smoke associated with the fuel. Several governments rewarded the manufacturing improvements by incentivising the purchase and use of diesel cars.

But the policy has backfired.

Going into reverse

First, there have been problems with the particle traps - some drivers have removed them because they sometimes don't work properly unless the car is driven hot.

Second, the diesels are still producing nitrogen dioxide (NO2), which irritates the lungs of people with breathing problems. Diesels make several times more NO2 than petrol cars.

Now, in order to meet European air pollution laws, politicians are being forced into an embarrassing U-turn, telling drivers that they've decided they don't much like diesels after all.

MPs in the UK have mooted a scrappage scheme for diesel cars, while the mayor of Paris has called for a ban.

Several European nations are currently in breach of EU clean air laws.

The EU’s NO2 limit was exceeded at 301 sites in 2012, including seven in London. The concentration on Marylebone Road was more than double the limit.

Districts in Athens, Berlin, Brussels, Madrid, Paris, and Rome are also exceeded the ceiling.

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Not just carbon: Key pollutants for human health

Particulate matter (PM): Can cause or aggravate cardiovascular and lung diseases, heart attacks and arrhythmias. Can cause cancer. May lead to atherosclerosis, adverse birth outcomes and childhood respiratory disease. The outcome can be premature death.
Ozone (O3): Can decrease lung function and aggravate asthma and other lung diseases. Can also lead to premature death.
Nitrogen oxides (NO2): Exposure to NO2 is associated with increased deaths from heart and lung disease, and respiratory illness.
Polyaromatic hydrocarbons (PAHs), in particular benzo a-pyrene (BaP): Carcinogenic.
line
Politicians are now scurrying to persuade the courts that they are obeying an EU demand to clean up the air as soon as possible.

The Paris mayor said at the weekend that she wanted the city to become ‘semi-pedestrianised’, with a ban on diesel cars in the city centre and some neighbourhoods given entirely to residents’ cars, delivery vehicles and emergency vehicles.

"I want diesel cars out of Paris by 2020," she said.

Ms Hidalgo hopes that her plan will improve the quality of the air in a city where, on average, people live six or seven months less than those who are not exposed to the same levels of pollution.

Adding electric vans and putting limits on tourist buses would also help lessen the public health risk, she said.

Premature death

Bikes are expected to become the favoured form of transport, with cycle lanes doubled by 2020 in a $141m (£90m) plan.

The Mayor of London, Boris Johnson has promised to halve pollution, spending around $516m (£330m) to bring 2,400 hybrid buses, zero-emission taxis and 10,000 street trees. The announcement came weeks after he was forced to accept that Oxford Street has some of the highest levels of NO2 in the world.

Central London will also have an 'Ultra Low Emission Zone' in 2020. Mr Johnson has previously faced criticism from health and environment lobby groups complaining that he was dragging his feet in meeting EU targets.

The UK government says it is responding to EU demands by bringing forward new plans. Labour say the government has ignored the issue - they demand low-emissions zones in all of the UK’s major cities.

ship exhaust Shipping is also a major contributor to air pollution
According to the European Environment Agency, air pollution is the top environmental risk factor for premature death in Europe; it increases the incidence of a wide range of diseases.

Particulate matter (PM) and ground-level ozone (O3) are the most harmful pollutants.

Vehicles are by no means the only source of pollutants – some industries are major polluters too, and shipping in some places. But the politicians who run Europe’s biggest cities have protested that they cannot control pollution from industry elsewhere that drifts into their area.

With so many nations failing to meet pollution laws, the EU is under pressure to relax air standards.

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heebeegeetee

28,591 posts

247 months

Thursday 11th December 2014
quotequote all
This is the problem with only getting your info from the Daily Mail (which is where that source originated from I believe).

To read that article you could think that none of it applies to petrol engines - but it does, petrol engines cause much the same harm, with some difference between the two. It's ridiculous imo to differentiate between petrol and diesel in this regard.

I understand that Paris is looking to ban all internal combustion engines from the central areas, not just diesel.

ST KEV 53

12 posts

111 months

Wednesday 17th December 2014
quotequote all
I need a diesel car as I work a long way from home.

watchnut

1,161 posts

128 months

Monday 29th December 2014
quotequote all
old Boris might be in trouble if Oxford street is really bad on diesel fumes, as i believe it is only open to buses....which make massive amounts of dirty fumes

The French will not ban diesels from Paris, as just about every car in france is an Oil burner

Just shows that Eurocrats make up stats and figures without looking out of the window......

Laurel Green

30,770 posts

231 months

Tuesday 30th December 2014
quotequote all
watchnut said:
old Boris might be in trouble if Oxford street is really bad on diesel fumes, as i believe it is only open to buses....which make massive amounts of dirty fumes
Not to mention the taxis. wink

Escort Si-130

Original Poster:

3,269 posts

179 months

Monday 26th January 2015
quotequote all
It was from BBC, not Daily Mail.

heebeegeetee said:
This is the problem with only getting your info from the Daily Mail (which is where that source originated from I believe).

To read that article you could think that none of it applies to petrol engines - but it does, petrol engines cause much the same harm, with some difference between the two. It's ridiculous imo to differentiate between petrol and diesel in this regard.

I understand that Paris is looking to ban all internal combustion engines from the central areas, not just diesel.

Escort Si-130

Original Poster:

3,269 posts

179 months

Monday 26th January 2015
quotequote all
There is more taxis than Buses using Oxford Street. Both do st loads of miles, like HGV's etc. What pisses me off with diesels is the idiots that buy them just for A-B because of they think they are getting better value, but 90% of the times those people that have not done their homework end up paying more, due to higher price of the fuel, short journeys do not warrant the diesel, the parts are pricey and servicing tends to be more.

watchnut said:
old Boris might be in trouble if Oxford street is really bad on diesel fumes, as i believe it is only open to buses....which make massive amounts of dirty fumes

The French will not ban diesels from Paris, as just about every car in france is an Oil burner

Just shows that Eurocrats make up stats and figures without looking out of the window......

bearman68

4,642 posts

131 months

Monday 26th January 2015
quotequote all
Clearly to reduce London Nox levels, you need to ban buses? (Well according to Top Gear, you do)

Fastdruid

8,623 posts

151 months

Monday 26th January 2015
quotequote all
heebeegeetee said:
To read that article you could think that none of it applies to petrol engines - but it does, petrol engines cause much the same harm, with some difference between the two. It's ridiculous imo to differentiate between petrol and diesel in this regard.
Where "Much the same" = "20x less"

heebeegeetee

28,591 posts

247 months

Tuesday 27th January 2015
quotequote all
Fastdruid said:
Where "Much the same" = "20x less"
Where do you get that from?

PeterGadsby

1,303 posts

162 months

Tuesday 27th January 2015
quotequote all
Regarding buses in London - Some buses run on Hydrogen, some buses are now hybrid (like the one shown on Top Gear)

Just my 2p

- Pete

PeterGadsby

1,303 posts

162 months

Tuesday 27th January 2015
quotequote all
Regarding buses in London - Some buses run on Hydrogen, some buses are now hybrid (like the one shown on Top Gear)

Just my 2p

- Pete

The Turbonator

2,792 posts

150 months

Tuesday 27th January 2015
quotequote all
Escort Si-130 said:
What pisses me off with diesels is the idiots that buy them just for A-B because of they think they are getting better value, but 90% of the times those people that have not done their homework end up paying more, due to higher price of the fuel, short journeys do not warrant the diesel, the parts are pricey and servicing tends to be more.
You mean like nearly everybody who buys a new car these days.

All my friends and family have all bought diesels, despite me telling them that because of the mileage and type of driving they do, it really is false economy. It falls on death ears though, and all I get in return is that I'm an idiot because the MPG is so much higher. I've given up now, because it seems people can quite defensive when you try and talk about the higher cost at the pump, servicing, reliability of DPFs, EGR Valves, etc. They can't look past the MPG figures and lower VED.

They're now even telling me that I'm a fool for not getting rid of my petrol and that if I traded it in for a diesel, I'd get twice the MPG.

crossy67

1,570 posts

178 months

Tuesday 27th January 2015
quotequote all
Escort Si-130 said:
What pisses me off with diesels is the idiots that buy them just for A-B because of they think they are getting better value, but 90% of the times those people that have not done their homework end up paying more, due to higher price of the fuel, short journeys do not warrant the diesel,
The old Piston heads regurgitated Topgear diesel hatred again.

We've owned diesels for probably the past 15 years, and petrol's too. Our current Scenic 1.5dci (I know, I'm waiting for things to fall off or out) returns 65mpg and apart from wiring faults found on all Scenics it's been fine. I think the secret is to but really worthless cars and run them until they drop, that way you're not forced to buy the expensive fixes.

Fastdruid

8,623 posts

151 months

Tuesday 27th January 2015
quotequote all
heebeegeetee said:
Fastdruid said:
Where "Much the same" = "20x less"
Where do you get that from?
http://uk-air.defra.gov.uk/assets/documents/reports/cat05/1108251149_110718_AQ0724_Final_report.pdf

8. A new Euro 5 petrol car emits about 96% less NOx than a pre-catalyst vehicle. However,
the RSD data does show that NOx emissions from Euro 1/2 and to some extent Euro 3
are higher than either the UK emission factor estimates or HBEFA. These results imply
that catalyst degradation, or more accurately, the emissions control system used on petrol
vehicles as a whole, is more important than previously thought and that older catalystequipped
cars are important emitters of NOx.

9. For diesel cars/vans the RSD suggests that there has been little change in total NOx
emissions over the past 20 years or so.

11. Considering emissions of NOx as a function of Vehicle Specific Power (VSP) shows that
under higher engine load conditions there is a clear increasing emission of NOx for Euro 3–
5 diesel cars that is not apparent for older generation vehicles. Indeed, Euro 3–5 diesel
cars can emit up to twice the amount of NOx under higher engine load conditions compared
with older generation vehicles; possibly the result of the increased use of turbo-charging
in modern diesel cars.

15. For base case conditions i.e. unadjusted most recent UK/London inventory estimates, the
downward trend in NOx is dominated by reductions in emissions from petrol vehicles. Over
the period 2002–2009 the NAEI calculations for UK urban emissions show a reduction
in NOx from diesel vehicles of about 24%. Taking account of the RSD emissions data
reverses this downward trend for diesel vehicles to an increase in NOx emissions of 18%
over the same period because of the increase in diesel vehicles (cars and LGVs) together
with RSD that suggests that NOx emissions have not decreased. This is an important
change to projected emissions over that period. Nevertheless, this increase in diesel NOx
emissions is still more than off-set by decreases in petrol vehicle NOx emissions.

heebeegeetee

28,591 posts

247 months

Tuesday 27th January 2015
quotequote all
Fastdruid said:
http://uk-air.defra.gov.uk/assets/documents/report...

8. A new Euro 5 petrol car emits about 96% less NOx than a pre-catalyst vehicle. However,
the RSD data does show that NOx emissions from Euro 1/2 and to some extent Euro 3
are higher than either the UK emission factor estimates or HBEFA. These results imply
that catalyst degradation, or more accurately, the emissions control system used on petrol
vehicles as a whole, is more important than previously thought and that older catalystequipped
cars are important emitters of NOx.

9. For diesel cars/vans the RSD suggests that there has been little change in total NOx
emissions over the past 20 years or so.

11. Considering emissions of NOx as a function of Vehicle Specific Power (VSP) shows that
under higher engine load conditions there is a clear increasing emission of NOx for Euro 3–
5 diesel cars that is not apparent for older generation vehicles. Indeed, Euro 3–5 diesel
cars can emit up to twice the amount of NOx under higher engine load conditions compared
with older generation vehicles; possibly the result of the increased use of turbo-charging
in modern diesel cars.

15. For base case conditions i.e. unadjusted most recent UK/London inventory estimates, the
downward trend in NOx is dominated by reductions in emissions from petrol vehicles. Over
the period 2002–2009 the NAEI calculations for UK urban emissions show a reduction
in NOx from diesel vehicles of about 24%. Taking account of the RSD emissions data
reverses this downward trend for diesel vehicles to an increase in NOx emissions of 18%
over the same period because of the increase in diesel vehicles (cars and LGVs) together
with RSD that suggests that NOx emissions have not decreased. This is an important
change to projected emissions over that period. Nevertheless, this increase in diesel NOx
emissions is still more than off-set by decreases in petrol vehicle NOx emissions.
Ok, as I thought, you're referring to just one pollutant. My point was that overall, petrol is better in some areas and vice versa in others.

I'm struggling to see the 20x less, but haven't had time to look at the report you linked to.

Interesting what it says re petrol engines and catalytic converters, bearing in mind that cats don't work when cold, such as starting up outside the owners house, driving in residential areas, outside schools etc. smile

Oh, and according to a post on another thread Nox is addressed with Euro 6 regs.


Edited by heebeegeetee on Tuesday 27th January 11:14

Fastdruid

8,623 posts

151 months

Tuesday 27th January 2015
quotequote all
heebeegeetee said:
Oh, and according to a post on another thread Nox is addressed with Euro 6 regs.
Which is actually the point of the report that despite the Euro regs it's made no difference.

Despite increasing regs there has been no decrease in NOx from diesel cars in 15-20years while Petrol cars have 96% less NOx (in the really real world rather than just in the lab) and that even the latest tech (SCR etc) actually has worse NOx in the urban environment.

I can't see Euro 6 making any difference.



Fastdruid

8,623 posts

151 months

Tuesday 27th January 2015
quotequote all
heebeegeetee said:
Ok, as I thought, you're referring to just one pollutant. My point was that overall, petrol is better in some areas and vice versa in others.

I'm struggling to see the 20x less, but haven't had time to look at the report you linked to.
Except that this "issue" is just about one pollutant, NOx so even if you were right it's irrelevant as it's all about the NOx.

http://www.telegraph.co.uk/motoring/news/10862975/...
http://www.theguardian.com/uk/2013/jan/27/diesel-e...

All the government has cared about has been CO2 (for which diesels are undoubtedly better) but no account is being taken of the health damage done by diesel fumes because CO2 emissions are seen as the sole benchmark for environmental responsibility.





mightymouse

1,438 posts

227 months

Tuesday 27th January 2015
quotequote all
Anyone see the Despatches programe on this last night ?

Horror shock - car does not do MPG that manufacture claims - blonde woman surprised, thinks she's been conned.
NOX emisions high - blonde woman surprised, thinks she's been conned.
Some minister admits ......we was conned...

readgetmecoat

heebeegeetee

28,591 posts

247 months

Tuesday 27th January 2015
quotequote all
Fastdruid said:
Except that this "issue" is just about one pollutant, NOx so even if you were right it's irrelevant as it's all about the NOx.

http://www.telegraph.co.uk/motoring/news/10862975/...
http://www.theguardian.com/uk/2013/jan/27/diesel-e...

All the government has cared about has been CO2 (for which diesels are undoubtedly better) but no account is being taken of the health damage done by diesel fumes because CO2 emissions are seen as the sole benchmark for environmental responsibility.
As one of your links says: "So what, if most of our driving is in town, should we be driving instead of a diesel? “There’s no easy answer,” says Molden. “Most technologies involve some form of trade-off. Petrol cars emit less NOx but more carbon dioxide, plus they use more fuel. Hybrids can be good in town, but less so on the motorway. Electric vehicles have no exhaust emissions but are expensive to buy and have limited range. The trouble is the official data informing these trade-offs isn’t complete or accurate. That’s why real-world emissions data is so valuable.”
Molden agrees with North’s suggestion that better-managed traffic flow is important in reducing NOx levels, but also points to the development of cleaner diesel engines that offer the low carbon dioxide output of today’s cars but with the promise of dramatically reduced NOx emissions."