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Discussion > Drs against Diesel : A subsidy mafia Front

I always assumed that the purpose of the mandatory twenty minute run at 80-90mph prior to the MOT/CT was to clean the surface of the catalyst (as well as getting both the engine and the radiator contents up to full operating temperature).

If I floor the accelerator of my diesel Volvo in 2nd gear and get it up to 5500rpm, after weeks of normal sedate running, it leaves an impressive black cloud behind in its trail. But only the first time, so I assume it is simply accumulated soot being blown out of the exhaust system.

Jan 7, 2017 at 10:16 AM | Registered CommenterMartin A

Martin A, the Italian Tune-Up worked on engines before catalysts. I don't know how much of a catalyst's benefits are actually from catalysing. Radiators in houses and vehicles don't do much radiating.

De-coking an engine was part of fairly serious DIY engine restoration. Cleaning all the bits of coke/carbon would have helped, but ensuring the valves closed properly was probably the most noticeable benefit.

Most engines that needed decoking probably had some other fault in the first place, not helped by wear and tear and reduced compression.

I do not see that increased temperature could help piston rings to rebed, but it would help valves to. Increased temperatures would help burn off the products accumulated by running at lower temperatures. Smoother flow of fuel/air mixes would increase mixing and combustion.

I can understand a catalyst working better at a higher temperature, but I do not understand whether there could be a lasting benefit.

Jan 7, 2017 at 12:07 PM | Unregistered Commentergolf charlie

Martin A, on reflection, the alternative line of query would be to do emissions tests on four diesel cars used to slow running in town and city conditions.

Car 1, give it an Italian Tune-Up
Car 2, give it a blast off 500 degrees C, nitrogen gas through the exhaust valves, manifolds and catalyser
Car 3, filll tank with Magic Potion additive treated diesel and run normally
Car 4, do nothing

Re test immediately, and then after another 1,000 miles.

Jan 7, 2017 at 4:57 PM | Unregistered Commentergolf charlie

What is the likelihood of this latest group of SJW rent seekers becoming a force to be reckoned with?

Jan 9, 2017 at 11:25 AM | Unregistered Commenterhunter


I Googled the lawyers orchestrating the VW dieselgate action in the UK

Imagine my surprise when this came near the top.

Ethically impure eh?

£5K apiece according to BBC anon

I see the FBI have arrested a couple of VW managers.... - in terms of real quantifiable actual environmental damage - just maybe - they could look at the Colorado gold mine incident that prompted the EPA to create the hoo-ha about VW?

Jan 9, 2017 at 7:31 PM | Registered Commentertomo

I have to put my hand up - yes I launched Doctors against Diesel. I have done air pollution research with children now for 15 years - and published the link between diesel soot in Leicester children's airway cells and lower lung function (in the New England Journal of Medicine) - and I have just published in the Lancet a cook stove intervention trial in Malawi (it did not work). Diesel I'm afraid is a low hanging fruit - it disproportionately contributes to PM and NO2 in London. Not the complete answer for sure - but if we can't deal with this major emission source - then there is little hope of protecting children's health by any other interventions. My conflicts - I'm paid by my University and NHS -and treat children with the most severe asthma. Just thought you would like to know.
Hi Jon - I note your comment on soot and I see you reference NO2 from diesel.
Please can you supply any supportable and verifiable reference on NO2 and mortality impacts? Or NO2 and any health impact at ambient concentrations?
Did you see this, and if so, do you think they were wrong to propose to leave the US limits unchanged?:$File/NO2+PA_external+review+draft.pdf

Please can you also comment on the difference between old and new technology diesel emisisons?
My understanding is that with diesel particulate filters the largest vehicle related PM source is from abrasion rather than combustion.

Please can you explain what analyses you have done of AQ policy alternatives as background to your decision to launch "Doctors against diesel"?
Thank you.

Jan 9, 2017 at 8:33 PM | Unregistered Commenternot banned yet

My understanding is that the goal posts have moved on diesel protests, and that now its all about NOx.

Real pity that Prof Grigg just did a hit and run here.
We hear a lot about the danger of echo chambers.

Jan 12, 2017 at 3:31 PM | Registered Commenterstewgreen

Times pg14
300 dead claim "A study by Public Health England and the Met Office"
- Claim that in certain days in March April 2014 10 days were smoggy.
- Says in normal period there are 600 premature deaths due to air pollution but then there were 600.
- Claims 1,600 people were admitted to hospital with severe respiratory or CardularVascular probs (meaningless unless quote background level !!)
- Claim that the smog was not Sahara snd but ammonia fertiliser from the continent PM2.5

Quotes :
Baroness Jones from Green Party
- and Anna Jones from Greenpeace "There is no room for doubt"
- Alan Andrews from Client Earth.

pg26 Corrections column :
'We said that 2 people/day die from starvation/thirst in UK CARE system, actually this is not the cause of death given on the death certificates. Sometimes dehydration or malnutrition is mentioned as a contributory factor.'

Jan 12, 2017 at 3:34 PM | Registered Commenterstewgreen

'We said that 2 people/day die from starvation/thirst in UK CARE system, actually this is not the cause of death given on the death certificates. Sometimes dehydration or malnutrition is mentioned as a contributory factor.'

Jan 12, 2017 at 3:34 PM | stewgreen

It is far better to blame an external cause of death, than have blame attributed to inadequate care, like lack of food or water.

Jan 12, 2017 at 4:02 PM | Unregistered Commentergolf charlie


My understanding is that the goal posts have moved on diesel protests, and that now its all about NOx."

I agree, the protests are increasingly about NOx impacts, but as far as I can tell, they have very little evidence to support them.

I also agree that it is a shame Prof Grigg chose to do a drive by - as a man who felt strongly enough to start a whole protest effort, one would hope that he'd welcome the chance to explain his position and the evidence upon which it is based.

Jan 12, 2017 at 4:53 PM | Unregistered Commenternot banned yet

Yeah, nby, his engine ran fine at initial trial, but I suspect he ran out of fuel. At least, we have zero emissions from him.

Jan 12, 2017 at 5:07 PM | Unregistered Commenterkim

nby & stewgreen, so is there a change in NOx production if you switch to bio-diesel, or even pure vegetable oil?

I still have this niggly doubt in my mind that diesel engines WERE favoured, because the Green Blob saw the probability of growing fuel for diesel engines. This IS perfectly feasible. Unfortunately, as more farmers started growing diesel, because of all the financial incentives, so food shortages grew, along with prices, adversely effecting those least able to afford it.

The Green Blob then had to change tactics to kill off the Diesel engine, despite there being no obvious alternative for trucks and buses.

Jan 12, 2017 at 5:50 PM | Unregistered Commentergolf charlie

Good points @Golf.
"The bulk of mandates continue to come from the EU-27, where the Renewable Energy Directive (RED) specified a 10 percent renewable content by 2020 but has been scaled back to the 5-7.5 percent range"
Targets vary for other countries eg upto 27% for Brazil.

Jan 12, 2017 at 9:46 PM | Registered Commenterstewgreen

Reply to Jan 12, 2017 at 4:02 PM @golf charlie
Today they apologise for mis-stating hunger and thirst killed
.. Yet they firmly state bad air killed when in reality it was only a contributory factor.
(I replied earlier but it went AWOL)

Jan 12, 2017 at 9:47 PM | Registered Commenterstewgreen

stewgreen 9:46, the USA has been producing the world's wheat surplus, which has then been sold off to feed hungry nations. Most of the grain delivered as humanitarian aid, with a UN Logo on the sacks, is US grown.

3/4/5 (?) years ago there was insufficient US surplus, because so much land had been turned over to growing diesel.

If you have access, search for wheat/corn prices and the timing of food shortages, and compare with US production of bio-diesel. There may be a pattern!

Jan 12, 2017 at 11:56 PM | Unregistered Commentergolf charlie

golf charlie:

"3/4/5 (?) years ago there was insufficient US surplus, because so much land had been turned over to growing diesel."

Do you have a source reference for that? US is primarily gasoline including in trucks AFAIK. There is a lot of ethanol production from grown crops which goes into gasoline but your claim of diesel production from wheat is new to me.Thanks for any sources you have.

Jan 13, 2017 at 4:09 PM | Unregistered Commenternot banned yet

not banned yet: you could start here, though not 100% reliable!

Jan 13, 2017 at 4:45 PM | Unregistered Commentergolf charlie

nby, or from The Guardian

Jan 13, 2017 at 4:48 PM | Unregistered Commentergolf charlie

Thanks gc but I'm not sure either reference supports your claim re the impacts of "growing diesel" - do you have specific quotes please?

I think this is the source World Bank Special Report of the time but perhaps there is another:

Note the graphic shown in figure one showing the global scale and shares of ethanol and biodiesel production has a misprint - the ethanol production figure in the text (para 3) is 50bn litres not 5bn as stated on the graphic.

Jan 14, 2017 at 2:21 PM | Unregistered Commenternot banned yet

PR from FoE is clearly basis of a BBC pollution reporting for Scotland

"according to new figures from Friends of the Earth (FoE) Scotland"
#2 it does NOT say what particle size !
Total Particle count
≠ Particle count from diesel.
(Be wary of jumping to conclusions

@SandyS pointed out a credibility problem, the super extraordinary claim that the street in a quiet small town like Crieff shows one of the highest readings in Scotland.

Jan 16, 2017 at 12:28 PM | Registered Commenterstewgreen

not banned yet, you can try this Telegraph article, written by Bjorn Lomberg in 2013:

If you google "biofuels" and "food prices" you can find many more, but those from before about 2010 were warning of what was starting to happen. From about 2010-15 it was happening, but blamed on Global Warming. Recent articles are about trying to blame someone else.

The World Bank Report 2008 that you link to does acknowledge some potential problems, but assumes they are someone else's problem to deal with.

Jan 16, 2017 at 3:54 PM | Unregistered Commentergolf charlie

Jan 16, 2017 at 12:28 PM | stewgreen

Volkswagen, and now others, are accused (correctly) of manipulating data testing technology and methodology, to achieve the results they wanted.

How can we be sure that FoE are not doing the same thing, particularly in Scotland?

Jan 16, 2017 at 4:02 PM | Unregistered Commentergolf charlie

I am committed to improving asthma care as well - its not mutually exclusive - you can see my video clip about our asthma research on youtube -

The main argument is that we need to remove the current diesel fleet (up to and including Euro 5) off our roads ASAP - if Euro 6 reduces emissions to those of equivalent petrol cares under real life conditions - then that would be great.

I can assure the group - I am really only concerned about protecting children's health - nothing else.

Jan 17, 2017 at 9:55 AM | Unregistered CommenterJon Grigg

Jon - thanks for coming back.

Are you interested in exchanging views and evidence on this topic?

If so, please could you take the time to read and respond to my comment up thread, posted Jan 9, 2017 at 8:33 PM.

Thanks for the link to your youtube clip. I'll watch it and post any comments later.

Jan 17, 2017 at 10:01 AM | Unregistered Commenternot banned yet

Jan 17, 2017 at 10:01 AM | not banned yet


Jon Grigg, I am intrigued (as is nby) about what it is about diesel engine emissions now, that is different/worse/better than say 20 years ago.

Jan 17, 2017 at 1:16 PM | Unregistered Commentergolf charlie