The war on NOx and diesel...

[Otispunkmeyer]

Max_Torque said:

There is also the fact that as a population we are living longer than ever before. Our "ageing" is going to cause us all significant issues in future as the old are not dying!

It's a trade off between convenience and risk, no absolutes. Lets face it, you can exceed some arbitrary NOx concentration limit (40ppm) and hence break a European law, but you are still quite free to smoke 20 fags a day! Of course when asked "are you worried about air pollution" the average VoxPop will say "oh, yes, very worried" and then jump into their car and drive off. In a world where more and more people are obese, and daily exercise is becoming the exception, NOx pollution is very low on the list of things to worry about!

The ONLY reason the politicians are suddenly getting their knickers in a twist is because some highly localised parts of the UK occasionally (in heavy traffic) fail to meet the EU "standards" and are in breech of EU legislation and hence we could be fined for non-compliance. And that is because some other faceless suit in Brussels has arbitrarily decided that 40ppm is the number below which we are all at risk. It's a bit like speeding, where 70mph = ok, 70.00000000001mph = Illegal, and yet the difference is RISK on either side of the arbitrary limit is immeasurable!

Indeed... and where here our politicians get their faces bent out of shape for the EU, I bet places like spain and italy, who'll have the same "problems", just dismiss it all out of hand. That is if its even crossed their minds in the first place.

[Terminator X]

Jimboka said:

The Turbonator said:

I think Diesel engines are already being pushed beyond their limits in terms of economy and pollution.

You're constantly hearing about DPF failures, EGR valve failures, turbo failures, DMF failures, etc etc.

The reason I stuck with petrol was because of all the horror stories I hear on these forums. Diesels make a lot of sense for company car drivers, short term PCP deals and long distance driving. But for my own personal car, that I plan to keep for many years, then no thanks.

Do you always believe what you read on the Internet? Most diesel drivers like me have had no such issues. I prefer how diesels drive . I am not on first name terms with my local Esso attendant. So a very happy owner, like 99% are..

Lucky? My ex diesel was a disaster zone stumbling from one problem to the next.

TX.

[DonkeyApple]

scherzkeks said:

Baryonyx said:

Funny, I was in Washington DC and Manhattan in the summer last year. It was extremely hot and dry, and it was fine. Nowhere near as bad as UK cities choked with diesel smog.

I lived in DC for 25 years. On a typical July/August summer day in DC you can cut the smog with a butter knife, and as another poster mentioned, the fumes from rich-running V8s are rather hard to miss. It's no better, just different.

The clue there is that you mention hot summer days. Smog is created from the chemical reaction triggered by sunlight. This is why cities with longer and stronger sunlight suffer more. It doesn't necassarily mean that there are more pollutants just that the chemical reaction that light triggers in a mix of monoxides and VOCs (both chucked out from cars of all types) is much stronger so much more ozone is produced.

You can also add another couple of factors which can make a city look worse than another. The first is the local climate and the second is prevalence of coal power stations. The Thames ensures that London benefits strongly from a more constant moving airflow, unlike DC which is more prone to stiller airs so less clearing of smog. I also believe that DC had a rather large coal burning power plant until around 5 years ago that made significant VOC contributions to the air quality.

But long and short, you can't easily contrast city pollution via smog comparisons as a city can have far more pollutants but without enough sunshine or with too much wind smog isn't formed.

[wack]

Terminator X said:

Lucky? My ex diesel was a disaster zone stumbling from one problem to the next.

TX.

I bought a 56 plate focus diesel as a 6 month runabout then sold it on through the garage that serviced it

18 months later I happend to be there when I saw it on the ramp

It'd had

DPF
NEW ENGINE
STEERING RACK
ELECTRIC PAS PUMP
DMF & CLUTCH

Dodged a bullet there

[wack]

Terminator X said:

Lucky? My ex diesel was a disaster zone stumbling from one problem to the next.

TX.

I bought a 56 plate focus diesel as a 6 month runabout then sold it on through the garage that serviced it

18 months later I happend to be there when I saw it on the ramp

It'd had

DPF
NEW ENGINE
STEERING RACK
ELECTRIC PAS PUMP
DMF & CLUTCH

Dodged a bullet there

[thelawnet]

DonkeyApple said:

But, if you divide the output of a bus by the average number of people being transported then unfortunately it becomes glaringly obvious that buses are not the issue. They are just very big, bright red and often seen with smelly exhaust plumes but they are not the offending articles.

Taxis, minicabs and vans. Those are the particulate emitters that are mostly responsible.

None of these vehicle types specifically need Diesel engines. If you omit vans on the grounds of being borderline and lesser in number, neither taxis or minicabs need to be diesel. One simple spot of legislation and they could all be petrol within a few years. And for vans, they will need proper particulate filters as will PLGs.

.

Uber are already mandating Priuses for new drivers

[jmcc500]

liner33 said:

charltjr said:

They've already addressed the NOx issue in the latest Euro 6 regs for diesel emissions. If anything I would expect to see tax breaks continue for the newer, lower emission cars rather than VED being increased because of the "NOx peril".

http://en.wikipedia.org/wiki/European_emission_sta...

Importantly though for diesels the emissions are not tested during dpf regeneration and levels of NOx rocket during this and regeneration becomes more and more frequent as the dpf fills up with ash, so hardly addressed in my opinion

Not true - emissions during regen are accounted for in the Ki factor.

Also, ash accumulates very slowly these days - low SAPS oils and decent fuels mean this is not an issue in the west. Still some problems in rural India/China I expect, but they're an emissions level or two behind us.

[mondeoman]

Diesels have DPFs, SCRs and soon (2017) Lean Nox Traps (LNTs) to hit the tailpipe emissions levels. Urea (Ad Blue) consumption will soar.

Gasolines are also getting GPFs to hit the particulate levels, so you could well start seeing GPF failures on petrols (unlikely, but possible, as it is an unproven technology).

Major cities around the world could well start banning diesels (as the chinese already do), so there could well be a resurgence of petrol power in the next 5 years.

On the positive side, we've never had it so good - 2-3 litre engines that easily pump out in excess of 200 - 300 ponies, with amazing economy when cruising, autoboxes that are becoming incredibly well matched to the engines, making the choice of power a bit moot tbh, and fuel prices coming down to well below (inflation adjusted) what we were paying 6 years ago.

Whats not to like?

[liner33]

jmcc500 said:

Not true - emissions during regen are accounted for in the Ki factor.

Also, ash accumulates very slowly these days - low SAPS oils and decent fuels mean this is not an issue in the west. Still some problems in rural India/China I expect, but they're an emissions level or two behind us.

Well the research paper I read stated than during regen NOx levels are up to 4 times higher than usual

Even if a car is used for motorway trips rather than shorter journeys the dof could well be half full by 50,000 miles

[jmcc500]

.

liner33 said:

jmcc500 said:

Not true - emissions during regen are accounted for in the Ki factor.

Also, ash accumulates very slowly these days - low SAPS oils and decent fuels mean this is not an issue in the west. Still some problems in rural India/China I expect, but they're an emissions level or two behind us.

Well the research paper I read stated than during regen NOx levels are up to 4 times higher than usual

Even if a car is used for motorway trips rather than shorter journeys the dof could well be half full by 50,000 miles

Yes, NOx during regen is higher, so you have to achieve a lower level during normal operation to offset the time that is spent in that condition, when combined the result must be below legal levels. I have read a few papers myself, though being responsible for Diesel emissions for an engine line at an OEM means I tend to go by the legislation that I and my team have to meet, rather than use a number from a paper out of context. That sounds harsh, not meant to be.

Please can you give a citation for your 50k miles DPF half full value? I am genuinely interested as I was responsible for (a different OEM) DPF control strategy in my former job and it was hellishly difficult to get accurate data on ash accumulation!

ETA: my previous 'not true' was with regards to emissions not being measured during regen. They are. The NOx emissions are higher, but the average during regen and non-regen operation (scaled based on regen frequency) must be less than the legal limit

Edited by jmcc500 on Tuesday 27th January 22:42

[Mr Gear]

thelawnet said:

Uber are already mandating Priuses for new drivers

Good! If only the black cabs would follow suit. But as you can imagine, their union will ensure they won't have to any time soon.

Take a walk down Oxford Street or The Strand and you can't avoid the stink that follows black cabs around... and I'm not talking about the drivers either.

[liner33]

jmcc500 said:

Yes, NOx during regen is higher, so you have to achieve a lower level during normal operation to offset the time that is spent in that condition, when combined the result must be below legal levels. I have read a few papers myself, though being responsible for Diesel emissions for an engine line at an OEM means I tend to go by the legislation that I and my team have to meet, rather than use a number from a paper out of context. That sounds harsh, not meant to be.

Please can you give a citation for your 50k miles DPF half full value? I am genuinely interested as I was responsible for (a different OEM) DPF control strategy in my former job and it was hellishly difficult to get accurate data on ash accumulation!

ETA: my previous 'not true' was with regards to emissions not being measured during regen. They are. The NOx emissions are higher, but the average during regen and non-regen operation (scaled based on regen frequency) must be less than the legal limit

Edited by jmcc500 on Tuesday 27th January 22:42

For VAG cars software like Vagcom can show the ash levels in the dpf , of course these vary depending on use , I know our car was 75% full by 75k . The dpf on our car only carries 45g of ash before needing replacement

A friend of mine had dpf failure at 130k (£1800)in his 535d and he spends most of his time on motorways. BMW told him he had done well

[DonkeyApple]

Mr Gear said:

thelawnet said:

Uber are already mandating Priuses for new drivers

Good! If only the black cabs would follow suit. But as you can imagine, their union will ensure they won't have to any time soon.

Take a walk down Oxford Street or The Strand and you can't avoid the stink that follows black cabs around... and I'm not talking about the drivers either.

I've always been surprised at how crap the running gear of black cabs is. Obviously it has to tollerate and awful lot of abuse but they kept using that ghastly diesel units for years. I think they use a Nissan unit but it still feels like a power plant from the 20th century. As do the gearboxes.

It's a shame drivers are switching to the Merc van but I'm pretty sure original cans could quite easily be fitted with better power plant and gearboxes.

But before laying all the blame on black cabs, does anyone remember the massive boom in minicabs after the CC was introduced. There are many more Hounslow Carriages than Hackney Carriages driving around London.

[braddo]

DonkeyApple said:

I've always been surprised at how crap the running gear of black cabs is.

Agreed. I've always been shocked at how poorly their ride is too.

I would love for Toyota to buy the London Cab Company and develop the current shape cab with a Prius-esque drivetrain. The alternatives seen elsewhere for low emissions cabs are absolutely frightful looking minivans. It would be very sad if the London Cab shape disappears from London's roads (I won't miss their emissions though!)

[GroundEffect]

SCR and AdBlue will be more common with Euro 6.2 rather than Euro 6.1 (which is now in effect).

[JonnyVTEC]

GroundEffect said:

SCR and AdBlue will be more common with Euro 6.2 rather than Euro 6.1 (which is now in effect).

Its effective from Sept 15 isn't it?

6.2 is basically US Tier3 so expect higher dosing rates.

[sparkyhx]

90% reduction of NOx on LPG - maybe they will make it even cheaper? Its already better cost wise than diesel equivalent

[DonkeyApple]

braddo said:

DonkeyApple said:

I've always been surprised at how crap the running gear of black cabs is.

Agreed. I've always been shocked at how poorly their ride is too.

I would love for Toyota to buy the London Cab Company and develop the current shape cab with a Prius-esque drivetrain. The alternatives seen elsewhere for low emissions cabs are absolutely frightful looking minivans. It would be very sad if the London Cab shape disappears from London's roads (I won't miss their emissions though!)

I agree. Would be good to see a modern equiv of the current style rather than an ever growing number of German minivans which are starting to make London look unnecessarily 'continental'.

Problem with the Prius idea is that it's a bit of a wheeze in London as it doesn't really work as all the stop-start short journeys mean they are never charged and always running on fuel but get the tax benefits of being an EV etc.

A well silenced, small, modern petrol unit with a modern auto box like the zf8 would be a huge improvement.

[GSE]

What about carbon neutral vegetable oil as a substitute for Diesel? How does it compare in terms of NOx and particulate emissions? Some years ago I used to run a Peugeot 405 on it - the smell from the exhaust seemed far less acrid than the smell from Diesel. Strangely the price of Veggie oil went up such that it became more expensive than Diesel...

[The Turbonator]

swerni said:

The Turbonator said:

Here's an idea.

Why not scrap the current VED scheme and tax cars solely on engine capacity size?

Make petrol and diesel the same price at the pumps.

Scrap manufacturers quoting combined MPG figures and instead quote only the urban and extra urban figures.

This way, the public can make an informed decision on whether choosing a diesel or petrol engine.

If they do low miles in the city, then they would be able to see that a petrol would be better. If they have a high annual mileage, with mostly motorway driving, they should be able to see that a diesel would be better.

This way the amount of diesels in city centres would decrease, thus lowering NOX levels in the city centres but we'd still have plenty of diesels on the motorway, keeping the CO2 levels down.

Edited by The Turbonator on Tuesday 27th January 10:04

That's a bloody stupid idea

Yeah I admit, it was a stupid idea, I didn't think about supercharging, turbocharging, wankel engines and hybrids.

You could come up with a system where CO2, NoX gasses and particulate matter are all taken into account, when calculating a cars VED level. But as another poster said, why do all that when you could just scrap VED and add it onto fuel?