So the government is wanting diesel cars off the road. Im totally against this. Diesels are great cars. One of the prime reasons I bought a 1.3 Fiat diesel.
They are cheap to tax and a Diesel engine can still run well at 300,000 or more! I just think the government wants more money and its got nothing to do with the environment. Petrol cars produce a lot more C02 and nasties like benzene.

1) The government knows the majority of low tax cars of £30 a year and less are diesels. Get them them off the road and people will have to get a petrol car with higher car tax or a new petrol car costing £170 a year tax.

2) Diesels have excellent MPG around 50mpg urban for a small I.3 diesel, compared to around 30 mpg for a petrol of same size. That means diesel drivers visit the pump less often and buying less fuel means less fuel tax.

3) Diesel engines last far longer than petrol engines and so people hold on to them a lot longer. A diesel can live up to 300,000 miles! Most petrol engines need a rebuild after 100,000.
This is bad news the government does not want people hanging onto old cars they want them paying the taxes on a new car.

I dont think its got anything to do with the environment, my little diesel fiat is very clean and I know its petrol equivalent would pump out a lot more CO2. The most recent DPFs are very effective. Petrol engines emit benzene from combustion and benzene causes leukaemia. Diesels do not emit benzene.

In all I think encouraging people to give up their diesels is a big con.

While I'm not getting into the politics of this, it's interesting to note that while the press has concentrated on Diesels (anything less than Euro 6, pre 2105 pays fee) it also affects petrol and earlier hybrid cars. Basically pre 2006 (Euro 4) cars will have to pay the proposed £10 per day fee.

Robert G8RPI.

This has been discussed several time on here and it seems people will happily buy into what the press say without thinking for themselves. Essentially you're right in a lot of what you say, environmentally diesels are no worse than petrol cars, they use less fuel emit less CO2 DPFs are very effective the tail pipe of my now 30,000 Euro 6 car is still silver inside with no carbon deposits.

The down side is that they produce Nitrogen Oxides these have been linked to respiratory conditions and as such the European Parliament had imposed rules regarding what they deem to be acceptable levels of these nitrogen oxides in the air.

In the first few days of 2017, in London and some other cities in the UK the levels of these chemicals where found to exceed what should have been the quota for the whole year, as a result the government now faces fines from Europe if they don't get things under control.

On important thing to remember is that heavily urbanised areas especially London are filled with busses and taxis all of which are diesel. There are very few private diesel cars in central London compared to the busses and taxis, but the policy is to save congestion and reduce pollution everyone should be forced on to public transport and so no one is willing to tackle the problems caused by public transport.

In Norwich about 15-20 years ago they made a major route though the city busses and taxis only to reduce pollution afterwards testing showed that exhaust pollution had dropped by 15% and hailed it an amazing success. Reading between the lines though the implication was that 85% of the problem came from busses and taxis.

The government here have stated that they are not going to declare a war on diesel cars because it is an urban issue and If everyone went out and bought a petrol car tomorrow our CO2 emissions would spiral out of control.

I crunched some numbers the other day regarding the diesel 2.0 fiat 500x and the petrol 1.4 fiat 500x
Both have 140hp both essentially identical cars, although the diesel was a 4x4 so heavier. The outcome was that over 100,000 miles the petrol car would produce about 1500kg of additional CO2 more than the diesel covering the same distance. Which is the weight of the whole car just in CO2 !!

People like to ignore this when trying rubbish diesels and claim their petrols are oh so much cleaner and better

I'm going to go out on a limb as imagine you used book numbers on that calculation rather than measured tail pipe emissions in that.

End of the day government was told it was a bad idea before and during and 10 years after the horse has gone they are bolting the gate. They don't have a hope in hell of meeting their local pollution targets which incidentally the petrol engines they've been taxing heavily are much better at (10-15 times by most in use measures). So for them it's a "quick win".

Entirely sure the focus will shift back to petrol or whichever fuel source is majority transport in due course..

Incidentally VW do produce the cleanest Euro 6 diesel it only produces twice the legal limit of particulate matter in use..other manufacturers (including fiat) produce up to 5x..

StevenRB45 said:

I'm going to go out on a limb as imagine you used book numbers on that calculation rather than measured tail pipe emissions in that.

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You're probably not really going out on a limb, I've not tested both cars with read world results to come by those numbers.

We do know that bother petrols and diesels fail across the board to match claimed CO2 figures in real world testing.

Of course in local emissions targets petrol cars are on paper the cleaner alternative. Until a couple more years when we have people throwing their hands in the air and complaining about the chemicals petrols cars emit and CO2 levels and petrol particulates.... and so the same arguments go on.

Petrol engines needing a rebuild after 100k miles? CO2 pollution?

My Volvo V70 2.4 did 365k kilometers on an LPG conversion, would have needed a head rebuild (a few valves running out of adjustable range) around 400k kilometers, and emitted less CO2 than most diesels.
As an asthma patient I definitely know which tailpipe I rather sniff: not the car with a diesel engine, nor the one with a direct injected petrol engine.
As a vegan hippie, I know the animal based foods industry is causing more CO2 emission than any other industry or cars/busses/lorries.

To keep the air quality in the cities reasonable it is necessary to promote minimal use of cars and have them ánd public transport run on LPG, CNG, LNG, hydrogen, or electricity.

To keep overall climate change in check, cars shouldn't be the focus anyways, although every bit helps and I believe hydrogen (produced with wind/solar/waterstream electricity) would be the best solution.

The issue is the current system has driven the wrong behaviour from consumers and manufacturers. Diesel is very good at moving heavy weights long distances efficiently (although there are moves to use CNG in road haulage instead). But if you don't move heavy weights or long distances and travel a lot more in town or short journeys it's terrible at that and as a result produces much higher emissions than claimed. Petrol cars warm up faster so have less issues with this also while you don't want to sit sniffing a petrol exhaust all day in town it's better than pumping class 1 carcinogens in to public spaces. The tax system effectively removed free choice for business users to a large extent, so even if you know your usage cycle doesn't fit the optimum you will pay through the nose for petrol.

Focussing relentlessly on producing co2 numbers on a treadmill has pushed technology in the wrong direction. So we now have downsized turbo petrol and diesel cars with direct injection. These vehicles have no chance of meeting any of the numbers they are meant to and air quality measurements bear that out.

Incidentally they don't last as long either, the 1560 diesel in our Citroen has a reputation for exploding between 8-10 years the petrol in the Mazda has been known to last well over 300k on the original parts (even the timing chain). I expect in the full ness of time ecoboost and tsi engines will also gain a reputation for expensive mechanical death at 8 to 10 years.

StevenRB45 said:

while you don't want to sit sniffing a petrol exhaust all day in town it's better than pumping class 1 carcinogens in to public spaces.

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http://scienceblog.cancerresearchuk...definitely-cause-cancer-should-we-be-worried/


"Notably, IARC hasn’t reclassified petrol exhaust in the same way – that’s still sitting down in Category 2B, along with coffee, pickled vegetables, and mobile phones as merely ‘possible’ causes of cancer. What’s the difference?

“Petrol exhaust contains similar chemicals to diesel, but petrol engines emit much lower amounts of fine particles,” says Phillips, “so it’s much less able to get stuck in the lungs in the same way as diesel exhaust.”

On top of this, he adds, it’s harder to study exposure to petrol exhaust as it’s so common in society, and finding an ‘unexposed’ group to compare with is harder."

They should come to Belgium, plenty of diesels over here, petrol only gained popularity in the past few years over here and it's still heavily overshadowed by diesels unfortunately...

AndyRKett said:

http://scienceblog.cancerresearchuk...definitely-cause-cancer-should-we-be-worried/


"Notably, IARC hasn’t reclassified petrol exhaust in the same way – that’s still sitting down in Category 2B, along with coffee, pickled vegetables, and mobile phones as merely ‘possible’ causes of cancer. What’s the difference?

“Petrol exhaust contains similar chemicals to diesel, but petrol engines emit much lower amounts of fine particles,” says Phillips, “so it’s much less able to get stuck in the lungs in the same way as diesel exhaust.”

On top of this, he adds, it’s harder to study exposure to petrol exhaust as it’s so common in society, and finding an ‘unexposed’ group to compare with is harder."

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Strangely enough you are linking something I've read (and possibly even linked in the panda thread..can't remember it's definitely familiar.) Difference would be the particulate matter as stated by the article. You can buy petrol engines with more Bhp than your golf that produce a similar amount of CO2 (look up Mazda 3 skyactiv G 2.0 163 if you feel the need).

However these do not require a device in the exhaust that converts amounts of coarse particulate matter (which is cancerous) into fine particulate matter (which is even more cancerous as it can cross cell membranes more easily). So yeah that would be why diesels are classified worse..

It's interesting that the IARC article is fairly old, and the data on petrol engines even older.
The latest direct injection petrol engines produce fine particultes and may even be worse than a similar power diesel with a DPF.

Robert G8RPI.

I think I might buy a donkey at least there no road tax to pay?

g8rpi said:

It's interesting that the IARC article is fairly old, and the data on petrol engines even older.
The latest direct injection petrol engines produce fine particultes and may even be worse than a similar power diesel with a DPF.

Robert G8RPI.

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Very probably true, if only someone had perfected a way of indirectly injecting the fuel. I imagine if such a thing existed it would solve the issues surrounding inlet coking and as a by-product produce much lower particulate emissions.

Of course the fixation on CO2 has driven us away from indirect injection with a catalyst which in terms of local pollution is the best solution for an I.c.e. engine and even better if combined with lpg. It's almost as though taxation and emissions framework has driven the wrong behaviour.

StevenRB45 said:

You can buy petrol engines with more Bhp than your golf that produce a similar amount of CO2 (look up Mazda 3 skyactiv G 2.0 163 if you feel the need).

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I'm still more than happy with my diesel and you can't put the roof down on the Mazda

AndyRKett said:

View attachment 177495

I'm still more than happy with my diesel and you can't put the roof down on the Mazda

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But if you had an mx5 you'd get similar mpg to the golf! Would have been great on the trip France, room for a toothpick and everything.

Yes I may be being facetious

That site may have an axe to grind I feel real world figure is just plain wrong...I looked up mine apparently according to them it does 35mpg (note my fuelly signature below for a fact check) . The new 3 can and does do mid 40s (calculated average not a website taking the manufacturers figure and knocking off 25%). But I'm sure they aren't pushing an agenda.

The Golf doesn't appear to fair to well either on their adjusted real world given you say you get 60 out of it. Strangely enough their real world figure for the ds3 is the most amusing as well as 81mpg mpg minus 25% is still 61..only out by 15mpg. Suppose that just proves if you are going to lie tell a whopper.

I suspect the real world test follows a set course with hills and higher speeds as well as town driving etc, tbh I have no idea what my car gets normally because I'm usually in too much of a hurry and overtaking tractors and lorries on rural roads takes it toll on the MPG. Then again I rarely encounter hills and most of my driving is between 50mph and 70mph

If you just go by the manufacturers claimed figures though they are still a long way apart

I suspect the adjusted real world test involves taking the claimed figure and multiplying it by .75 (or there abouts some are a little closer than others) but anyway.

My issue with this all at the end of the day is they have built cars that can't work as designed in real world conditions. I'm sure you remember which 2 cars we have by now, if the system wasn't broken they should not be comparable. Literally the ds3 should get nearly twice the mpg of the 3. But in the same road conditions, with the same drivers one gets within 10 to 15% of the other. So when it's claimed to do 74mpg and in doing so gets 99k/GM with less than the required amount of particulate to pass Euro 6 that is all well and good. But it under performs by 38%, so there's a reasonable chance it's actually putting out nearly 140g/km..which is deeply unimpressive for a car of that size. God only knows what the actual particulate count is. If that's the standard of the best most recent ones then perhaps scrappage of the older ones is slightly sensible.

So to sum up, I don't believe the figures given, even the most recent diesels chuck out more than they should, petrol Di is a daft development that causes more problems than it solves...and er downsizing is only good on a rolling road. Think that covers it

As previously stated a 2.0 Diesel 500x emits 1400kg less CO2 than its petrol equivalent

Assuming a car was meeting euro6 requirements exactly for its entire life the NOX emissions from a diesel would be just 12.8kg and particulates released into the atmosphere would be 800grams for a car that covered 100,000 miles

CO2 is in essence harmless to us and already exists in the atmosphere however the more we produce the more we change the balance of our atmosphere and the more acidic the oceans become as the earths water tries to dissolve the CO2 having a knock on effect with the entire balance of things.

I do agree in principle that pollution in any form is not a good thing from either diesel or petrol however what is more intrinsically harmful to the environment?
1400kg of CO2 verses 12.5kg of NOX and 800g of particulates.


(It's worth noting that petrol cars still emit particulate and NOX the particulate limits are the same as diesel and the NOX limit is 0.06g/km verses 0.08g/km for diesel)

AndyRKett said:

As previously stated a 2.0 Diesel 500x emits 1400kg less CO2 than its petrol equivalent

Assuming a car was meeting euro6 requirements exactly for its entire life the NOX emissions from a diesel would be just 12.8kg and particulates released into the atmosphere would be 800grams for a car that covered 100,000 miles

CO2 is in essence harmless to us and already exists in the atmosphere however the more we produce the more we change the balance of our atmosphere and the more acidic the oceans become as the earths water tries to dissolve the CO2 having a knock on effect with the entire balance of things.

I do agree in principle that pollution in any form is not a good thing from either diesel or petrol however what is more intrinsically harmful to the environment?
1400kg of CO2 verses 12.5kg of NOX and 800g of particulates.


(It's worth noting that petrol cars still emit particulate and NOX the particulate limits are the same as diesel and the NOX limit is 0.06g/km verses 0.08g/km for diesel)

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To take your example though the 500x has been tested and found to produce 6-12 times the harmful emissions it's allowed under Euro 6. In another test it's been found to switch it's anti pollution gear off after 22 minutes. As a result it's far worse than the worst direct injection petrol (worst I can find is the focus ecoboost 1.0 which in use meets EU 3 diesel standard for particulate emissions). Even with the assistance of a particulate filter the 500x diesel doesn't get within a mile of any emissions standard never mind 6. So probably a poor choice for your maths (if anything your golf would have made a better example it's far cleaner in use)

CO2 is a problem it should be reduced, there are many many possible ways of doing that. Most of which involve life style change which the government doesn't like, people tend to vote against that.

So apparently 1400kg versus 100kg + of pm matter released at street level where people are likely to breathe it. Quite literally choose your poison..

StevenRB45 said:

So apparently 1400kg versus 100kg + of pm matter released at street level where people are likely to breathe it. Quite literally choose your poison..

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Well I ballsed that up...should say 10kg! Although the nox emissions would be in that range. Posting on a phone has it's risks!