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.

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.

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

"Hi
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.
Jon"
+++++++++++++++++++
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?:

https://yosemite.epa.gov/sab/sabproduct.nsf//LookupWebProjectsCurrentCASAC/DA69AD128DDA195085258037004E1097/$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.

https://www.healtheffects.org/publication/executive-summary-advanced-collaborative-emissions-study-aces

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.

'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.

Stewgreen:

"@NBY
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.

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.
========

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.

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!

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.

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

https://en.m.wikipedia.org/wiki/Biofuel_in_the_United_States

nby, or from The Guardian

https://www.theguardian.com/environment/2008/jul/03/biofuels.renewableenergy

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:

http://siteresources.worldbank.org/INTOGMC/Resources/Biofuel_Dev_Outreac_Oct_2008.pdf

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.

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

http://www.telegraph.co.uk/news/earth/energy/biofuels/10520736/The-great-biofuels-scandal.html

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 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?

Hi
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 -https://www.youtube.com/watch?v=iA8FfhXIUGA

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.
Jon

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 | not banned yet

+1!

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.