My opinion on modern diesels. Do you agree?

[heebeegeetee]

dme123 said:

The EGR system is nothing to do with CO2 emissions, it's to reduce the (really very harmful) NOX emissions. The DPF isn't for CO2 either, it's to get rid of the carcinogenic soot.

You do realise it took studies on miners who had worked underground with diesel for 30 years to decide the soot was carcinogenic? Unlike the benzene in your petrol, emissions from which you emit on the neighborhood of every fuel station you fill up at, it was always known that benzene was highly carcinogenic.

The irony is that large quantities of petrol underground is far too dangerous to use. Diesel has to be used because it is much safer, and now from that people are using that experience to say that derv is m ore harmful than petrol.

[skyrover]

Diesel is far more harmful to humans than petrol, hence the reason countries like the USA and Canada essentially banned the stuff in passenger vehicle with draconian emissions laws.

Small petrol 2 strokes are pretty damn dirty though

Here is a big 6.2 litre V8 Ford Raptor vs a Fiat 500 and a leaf blower

https://www.youtube.com/watch?v=pDxQIHoTmxs

[Devil2575]

Burning any hydrocarbon produces crap you don't want. The answer is to move to EVs which in the short term shifts the combustion process to a power station where greater efficiency can be achieved and emissions better controlled. Also burning natural gas is far better than both Petrol or diesel in terms of pollution. Longer term power generation will move away from combustion processes.

[BGarside]

Devil2575 said:

Burning any hydrocarbon produces crap you don't want. The answer is to move to EVs which in the short term shifts the combustion process to a power station where greater efficiency can be achieved and emissions better controlled. Also burning natural gas is far better than both Petrol or diesel in terms of pollution. Longer term power generation will move away from combustion processes.

Always assuming a fleet of modern, efficient power stations and not old coal-fired stations and the odd ancient nuke, as we have in the UK. I doubt there is sufficient spare capacity in the UK to allow large numbers of people to start plugging in their cars.

Thanks to a culture of nimbyism in Britain no-one will tolerate anything like a power station being constructed within sight of their houses and so power stations close and new ones don't get built quickly enough. More renewables would help, but can't replace baseload generation plant and in any case the government has done its best to kill off the renewables sector.

Gas fired stations have been built because they are cheap and quick to construct, but where does the gas come from??

Without a coherent long-term plan for investment into new power generation capacity in the UK, electric vehicles are a pipe dream - keeping the lights on will be enough of a challenge...

[BGarside]

yonex said:

Dear God, the marketing got you didn't it?

Have a little read about the impact of industry. Specifically China, Russia, Brazil, India and then tell me how important the average motorists choice of propulsion is.

Surely it's the local impact of exhaust particulates in the UK that the DPFs are there for, and is something we have control over rather than the global emissions of industry, that we don't?!

China are choking on their industrial emissions in the same way that parts of the UK used to back in the 1950s and 60s, but those days are mostly gone and vehicle exhaust emissions are the primary source of inhaled emissions in most of the UK.

Why should we consider it acceptable to remove DPFs, any more so than removing petrol catalytic convertors??

[anonymous-user]

heebeegeetee said:

dme123 said:

The EGR system is nothing to do with CO2 emissions, it's to reduce the (really very harmful) NOX emissions. The DPF isn't for CO2 either, it's to get rid of the carcinogenic soot.

You do realise it took studies on miners who had worked underground with diesel for 30 years to decide the soot was carcinogenic? Unlike the benzene in your petrol, emissions from which you emit on the neighborhood of every fuel station you fill up at, it was always known that benzene was highly carcinogenic.

The irony is that large quantities of petrol underground is far too dangerous to use. Diesel has to be used because it is much safer, and now from that people are using that experience to say that derv is m ore harmful than petrol.

I was aware of that and I am also aware that we used asbestos for 4500 years before we realised that was harmful, but that doesn't make it any less harmful. It's not the deleterious effects of the fuel itself that causes much of a problem it's the tailpipe emissions, so the relative safety of the fuel itself is not all that relevant.

I do agree however that we should be looking at using vapor capture systems on gasoline filling pumps.

[heebeegeetee]

skyrover said:

Diesel is far more harmful to humans than petrol, hence the reason countries like the USA and Canada essentially banned the stuff in passenger vehicle with draconian emissions laws.

The US went for a low cost, high consumption policy, unsurprisingly given that it's an oil producer. For a developed nation the US has pretty shocking pollution figures per capita, and vies with China to be one of the dirtiest nations on the planet.

[Limpet]

AW111 said:

The thing I find odd is that much of the "new" diesel technology comes from the transport industry, where stellar miles are expected and reliability is paramount.
We had an engine in at work a few years ago, common rail, multi squirt, etc., with a power recovery rurbine geared to the flywheel to get that last bit of energy from the exhaust. Not been tried in cars yet, that I kniw of.


To me that proves the technology can work well and reliably, at least under some conditions.

I think a good part of it comes down to state of tune, and usage pattern.

A modern truck or bus diesel has a specific output of about half that of a typical modern passenger diesel, and in a vehicle that needs to earn its keep, is generally more likely to be in near constant use, so always up to temperature, and enduring fewer cold starts and short runs.

[Devil2575]

BGarside said:

Devil2575 said:

Burning any hydrocarbon produces crap you don't want. The answer is to move to EVs which in the short term shifts the combustion process to a power station where greater efficiency can be achieved and emissions better controlled. Also burning natural gas is far better than both Petrol or diesel in terms of pollution. Longer term power generation will move away from combustion processes.

Always assuming a fleet of modern, efficient power stations and not old coal-fired stations and the odd ancient nuke, as we have in the UK. I doubt there is sufficient spare capacity in the UK to allow large numbers of people to start plugging in their cars.

Thanks to a culture of nimbyism in Britain no-one will tolerate anything like a power station being constructed within sight of their houses and so power stations close and new ones don't get built quickly enough. More renewables would help, but can't replace baseload generation plant and in any case the government has done its best to kill off the renewables sector.

Gas fired stations have been built because they are cheap and quick to construct, but where does the gas come from??

Without a coherent long-term plan for investment into new power generation capacity in the UK, electric vehicles are a pipe dream - keeping the lights on will be enough of a challenge...

Assuming people charge cars overnight when demand is lowest then I don't think capacity is a massive problem.

Nimbyism is though. There will be more gas to help us in the short term if the Nimbys don't get their way and block fracking.

Edited by Devil2575 on Wednesday 1st July 11:49

[bp1000]

Funny this is, when you own a diesel and its doing 50mpg and you feel that momentary torque you will defend and be an advocate for running a diesel.

I tried them a few years ago, a bmw 335d and thinking back it wasn't all bad but it was a pretty numb driving experiencing. Despite having 2 turbos it didn't thrill as you revved it.

In reality it wasn't a money saving thing, the turbo actuators both went and it needed new thermostats, it was more expensive to start with with high service and fuel costs. It was pretty economical at times but ultimately i would still much prefer to own a golf R or similar.

I don't think i will ever go back to diesels. If i have to ever do a long commute i will make sure it is somewhere where i can take the train. If i ever need to travel up and down motorways it will likely be a big german luxo barge, i wouldn't care what is powering it, the company pays for it.

For everything else, there are plenty of tasty petrol cars, despite them getting more complicated too.

[anonymous-user]

BGarside said:

Surely it's the local impact of exhaust particulates in the UK that the DPFs are there for, and is something we have control over rather than the global emissions of industry, that we don't?!

China are choking on their industrial emissions in the same way that parts of the UK used to back in the 1950s and 60s, but those days are mostly gone and vehicle exhaust emissions are the primary source of inhaled emissions in most of the UK.

Why should we consider it acceptable to remove DPFs, any more so than removing petrol catalytic convertors??

My point is that they main offenders in the atmospheric soup are not motorists. The obsession with clamping down on them only serves to make cars less reliable and more expensive to maintain. Not to mention, probably more toxic to produce which would be the final insult.

[Tractor lad]

We didn't buy our E91 335d to save a few bob, we bought it because it was quick, subtle and carried a bit of kit. The 335i (E91) was nicer but a little unreliable.
Our VW diesel (California camper bought new) was diesel only.
Our Defender was diesel only.
None were good on fuel, all did their job well but only the 335d was reliable; the current version didn't appeal; I don't want AWD in a fast car (our Outback is a workhorse) and the handling was just a bit too blunt.
So M135i it was; after waiting a year or so to make sure the N55 engine was more reliable than the N54.

I don't dislike how good diesels drive, I don't moan about the low redline (some petrols are barely any higher revving) but the recent "developments" have killed them. Paris is banning them; that's just the start.

[heebeegeetee]

dme123 said:

I was aware of that and I am also aware that we used asbestos for 4500 years before we realised that was harmful, but that doesn't make it any less harmful. It's not the deleterious effects of the fuel itself that causes much of a problem it's the tailpipe emissions, so the relative safety of the fuel itself is not all that relevant.

I do agree however that we should be looking at using vapor capture systems on gasoline filling pumps.

I think you're missing the point.

The miners have had to work underground for 30 years in the vicinity of diesel engines before it became clear that some of them showed signs of cancer. How big a risk do you think that translates to you and me?

It's not that it's taken a long time to realise that soot is carcinogenic - it's that people have had to work in close confines for a long time before they developed tumours.

Personally I see it as proof that I'm highly unlikely to develop tumours from soot emitted from engines.

I imagine that derv is used underground over petrol because a) you'd need a lot more petrol, b) petrol is far more volatile and dangerous, c) petrol engines generate far higher quantities of carbon monoxide, a deadly killer underground.

Derv was used underground because it is far safer, yet now this very experience leads people to think that derv is more dangerous than petrol.

[Devil2575]

heebeegeetee said:

dme123 said:

I was aware of that and I am also aware that we used asbestos for 4500 years before we realised that was harmful, but that doesn't make it any less harmful. It's not the deleterious effects of the fuel itself that causes much of a problem it's the tailpipe emissions, so the relative safety of the fuel itself is not all that relevant.

I do agree however that we should be looking at using vapor capture systems on gasoline filling pumps.

I think you're missing the point.

The miners have had to work underground for 30 years in the vicinity of diesel engines before it became clear that some of them showed signs of cancer. How big a risk do you think that translates to you and me?

It's not that it's taken a long time to realise that soot is carcinogenic - it's that people have had to work in close confines for a long time before they developed tumours.

Personally I see it as proof that I'm highly unlikely to develop tumours from soot emitted from engines.

I imagine that derv is used underground over petrol because a) you'd need a lot more petrol, b) petrol is far more volatile and dangerous, c) petrol engines generate far higher quantities of carbon monoxide, a deadly killer underground.

Derv was used underground because it is far safer, yet now this very experience leads people to think that derv is more dangerous than petrol.

I don't think I agree with this assessment.

Firstly it's not just tumours that are the problem, it's respiratory problems as well. Cancer isn't the only thing that can kill you.

You cannot simply translate the length of time taken to discover that somethiong is dangerous to how dangerous it is. The human race discovered that fire was dangerous thousands of years ago and that mercury was poisonous only relatively recently. That doesn't mean that fire is a lot more dangerous than mercury, in fact most of us use fire uncontained in our houses, yet almost no one has uncontained mercury.

Diesel is safer because it doesn't burn easily and in a confined space where oxygen is at a premium fire is incredibly dangerous.

[willmagrath]

Ghost91 said:

willmagrath said:

I've had a diesel for 3 years now and yes I have had to change the DMF but most modern powerful petrols have them now too so it's no different. The cambelt has been changed, less than £350 and i've averaged 47mpg with very mixed driving. See 60mpg regularly on fast runs, close to 70 mpg in slower traffic.

Yes its a bit dull to drive but after a remap its now a type r beater and still returns great mpg

It is different because while new petrol cars have DMF's now, they aren't under the strain diesels are so they don't tend to ever need replacing like they do on a diesel

What car is this if you don't mind me asking? They do go well enough, a remap always helps!

True i guess, nut they are known to go on petrols with more torque, v8's, v6's etc. Its a 2004 fabia vrs

[heebeegeetee]

Devil2575 said:

I don't think I agree with this assessment.

Firstly it's not just tumours that are the problem, it's respiratory problems as well. Cancer isn't the only thing that can kill you.

You cannot simply translate the length of time taken to discover that somethiong is dangerous to how dangerous it is. The human race discovered that fire was dangerous thousands of years ago and that mercury was poisonous only relatively recently. That doesn't mean that fire is a lot more dangerous than mercury, in fact most of us use fire uncontained in our houses, yet almost no one has uncontained mercury.

Diesel is safer because it doesn't burn easily and in a confined space where oxygen is at a premium fire is incredibly dangerous.

I was specifically addressing a point on the soot being carcinogenic.

But you're still missing the point.

Diesel exhaust had the same classification as petrol as being 'likely to be carcinogenic'. This changed in 2012, after studies done on people who have worked underground with diesel engines for 30 years, so derv was changed to 'known to cause cancer'.

Obviously similar tests have not been done with petrol engines because petrol is just too dangerous to use underground or in confined spaces in the first place.

Fire or asbestos or whatever is known to harm as soon as you come into contact with. To find out if derv exhaust is carcinogenic they've had to put people to work underground with the stuff for 30 years. Above ground in the open air, how much exposure would we need to develop the same results?

I'd suggest more than a lifetime, so therefore I roll my eyes whenever I see mention of diesel exhaust being carcinogenic, especially when the speaker does not mention the known carcinogenicity of the benzene added to petrol.

(Thus: )

[Devil2575]

heebeegeetee said:

I was specifically addressing a point on the soot being carcinogenic.

But you're still missing the point.

Diesel exhaust had the same classification as petrol as being 'likely to be carcinogenic'. This changed in 2012, after studies done on people who have worked underground with diesel engines for 30 years, so derv was changed to 'known to cause cancer'.

Obviously similar tests have not been done with petrol engines because petrol is just too dangerous to use underground or in confined spaces in the first place.

Fire or asbestos or whatever is known to harm as soon as you come into contact with. To find out if derv exhaust is carcinogenic they've had to put people to work underground with the stuff for 30 years. Above ground in the open air, how much exposure would we need to develop the same results?

I'd suggest more than a lifetime, so therefore I roll my eyes whenever I see mention of diesel exhaust being carcinogenic, especially when the speaker does not mention the known carcinogenicity of the benzene added to petrol.

(Thus: )

Asbestos does not cause harm as soon as you come into contact with it. Not everyone who comes into contact with it develops asbestosis and it is a chronic condition generally caused by prolonged exposure. In this respect it is much like Benzene. It is technically possible to develop cancer from exposure to a single molacule of benzene as it is to develop asbestosis from a signgle fibre of asbestos, however continued exposure over a number of years make it significantly more likely.

The reason it took 30 years to find out that diesel fumes can cause cancer is precisely because the effects are chronic and not accute. The reason why it took a study of miners who worked in a confined space with diesel generators to determine this is because it's actually very difficult to determine exactly what has caused cancer. You needed a largish group of people all working in similar conditions to be able to show with any reasonable degree of accuracy what has caused it.
Just because we are not exposed to the same levels of diesel fumes as miners does not mean it will not cause cancer, it just means it is less likely. However with a large enough population of people living in urban centres where traffic levels are heavy being exposesed to these fumes on a daily basis you will see an increased incidence of cancer resulting from it.

It took an equally long time for people to realise that Benzene was a carcinogen.

[macky17]

daemon said:

With respect, your jag hasnt yet reached the age where it may have problems. Its a very complex car.

6 years old, 72k miles and been perfect other than a door lock.

[heebeegeetee]

Devil2575 said:

1. Just because we are not exposed to the same levels of diesel fumes as miners does not mean it will not cause cancer, it just means it is less likely.

2. It took an equally long time for people to realise that Benzene was a carcinogen.

1. Of course, and also we should remember that petrol exhaust is classified as 'likely to cause cancer'. As I say, I just find myself wincing a bit when I read of the carcinogenicity of diesel exhaust because people never mention the danger of petrol exhaust - it's almost as though they believe one is dangerous and the other isn't.

2. I thought that, like tetra-ethyl lead, the dangerous nature of the substances were perfectly well known before being added to petrol on a commercial basis.

[Devil2575]

heebeegeetee said:

1. Of course, and also we should remember that petrol exhaust is classified as 'likely to cause cancer'. As I say, I just find myself wincing a bit when I read of the carcinogenicity of diesel exhaust because people never mention the danger of petrol exhaust - it's almost as though they believe one is dangerous and the other isn't.

2. I thought that, like tetra-ethyl lead, the dangerous nature of the substances were perfectly well known before being added to petrol on a commercial basis.

You. may be right on the 2nd bit but it certainly didn't concern people until much more recently. For example Attitudes to benzene in the 1970s in the chemical industry were far different from today. It's only in the last 30-40 years where people have really started to pay more attention to the health risks.

And yes petrol is also a carcinogen. The difference being that the particulates produced when diesel is burnt are the problem, whereas it's the benzene in the unburnt petrol that is the issue. When it burns it tends to produce less crap, which is a general principle that you can apply to all hydrocarbons. The lighter they are the cleaner burning they tend to be.

Edited by Devil2575 on Wednesday 1st July 17:11