Why buy new diesel cars?

[Deleted member 65149]

. stupid diesel owners.

Your words. I wouldn't go that far, but if that's your opinion you're entitled to it.

I did say that many diesel owners (and government) were perhaps gullible for believing that diesels were the clean answer to motoring. I certainly did not say that every diesel owner on this forum was gullible. In the years that I've been a member I had gained the impression that most are well informed on motoring matters and would supply intelligent answers to my question about why people still buy diesels in spite of the relatively recent revelations about their dangerous emissions. Some members did just that, mainly admitting that cost savings were their priority. But a few others instead chose to come out with personal attacks on me and incredulous claims such as diesel emissions being cleaner than the air in the Alps (or some such comparison). They said the figures produced by various organisations were wrong, then made their own totally unsubstantiated claims that petrol engines produced far more harmful emissions. They may well do, but I haven't seen any evidence yet so have no option other than to believe the technical reports I have seen. Perhaps I'm gullible!

I've been accused of claiming to make a positive contribution to the environment by cycling. All I did was answer a poster who said I should cycle, which I occasionally do. He made the big deal of it, not me. As for all the personal jibes about my own choice of car, they're like people saying there's nothing wrong with beating up a few OAPs because people get shot in America. Perhaps you're right after all Yugguy! But as I pointed out at the beginning of this post, I didn't say that.

 

[tangey]

I do ride a bike, and I walk a lot. So does my wife. That's why our only car covers an average of around 4000 miles a year. :success

That's a very personal subjective view of success. If you drove 4,500 would it still be success ? what about 9K, 15K. At what annual mileage beyond 4000 are you successfully not contributing to the death of young children ? (to use your argument)

 

[400ixl]

Just a couple of very high level articles. One is quite old now but has the basics.

Emissions from petrol cars have been dramatically reduced by the introduction of catalytic converters, which oxidise pollutants such as CO to less harmful gases such as CO2. When compared to petrol cars without catalysts, catalyst cars have much lower CO, HC and NOx emissions, at the expense of CO2 emissions, which increase due to the oxidation of carbon monoxide to CO2. As a consequence of this, a catalyst car will also use slightly more fuel and become less efficient. However, despite these improvements, petrol cars with catalysts still produce more CO and HC than diesel cars, although exhaust emissions of NOx and particulates are much lower than diesel cars. In fact particulate emissions from petrol cars are so low that they are not routinely measured.

Vehicle Emissions | Air Pollution | City Diesel | LPG | CNG

HC - Hydrocarbons contribute to ground-level ozone formation leading to risk of damage to the human respiratory system. Some kinds of hydrocarbons, in addition, are both carcinogenic and indirect greenhouse gases.

Cars and air pollution

There are hundreds of documents out there that go into the detail of the damage that hydrocarbons do is greater to humans than NOx.

Not going to spoon feed you for something that is out in the public domain. Take your head out of the sand and go and look.

I can understand people not knowing this as its not been on the public agenda as the sensationalised story is about the global scandals and targets, but now you do, it is for you to go and do some research to educate yourself on the lack of knowledge you have on a topic you started.

First though you have to admit to yourself that there is an issue her that you did not understand and that it may alter your beliefs when you do that research.

There is no doubt that Diesels need cleaning up further, but when you take the human health element as you did, then you need to appreciate that certain petrol engines are actually worse.

So, why do people still buy new large engined petrol cars when they are so bad for human health (even if they may be better for the environment)?

And with that I will sign off from this thread as I can't see it going anywhere productive.

 

[ShinyF1]

New diesel vehicles are actually very clean. :bannana:

Especially VWs apparently

 

[ShinyF1]

I would have no problems buying a petrol car but there wasn't one available in my area at the time.

I do want to buy a petrol engined car next, want an interesting 6 cyl engine but don't want to stretch to a V8. What are my options in the used car market? Next to nil (for something I really want).

My perfect car would be a three year old CLS 350 CGI Shooting Brake, but the buggers at MB have decided that if you want a CLS SB of that vintage, then you must have a diesel. I get that this decision is based on supply and demand, but given that they made the saloon with the V6 CGI engine it's a bit of a shame. Trouble is I really to hanker after a CLS SB, so diesel it will have to be unless I can compromise and find an S212 E Class V6 CGI estate - they do exist, but there's not many of them, and I think they may have stopped making them before the first 212 mild facelift.

Heart says I'll probably end up with a CLS 350CDI....

I think there is going to be a bit of a taxation backlash on diesel drivers, which is unfortunate, but any arguments amount the relative merits of petrol v diesel are entirely dependent on model of car, type of usage, mileage etc which has already been mentioned on here. Each makes their own choice, but the fact remains that motoring using any fossil fuel is going to be bad for the environment in one way or another.

I have had my E320CDI for over ten years now and love it as I do, it does chuck out a fair amount of smog, and I have always slightly missed the petrol engine rev range. My wife recently bought a six year old petrol Mini Cooper and you know what, having driven it a few times, I love it.

Unfortunately the R129 plan may be indefinitely shelved - just wish the wife had been looking for a car three years ago when a nice SL320 would have been cheaper than the mini! What has happened to R129 prices? But that is a different subject for another thread...

 

[Yugguy]

Diesel as a driving force makes a lot of sense.

If you disregard emissions for a second, a diesel with an auto makes complete sense for the daily commute, low rpms do good mpg, lots of easy low-down torque.

However, yes, emissions are a concern. It seems to me that not enough r and d has been done into a decent nox removal system.

 

[KeithJG]

Diesel as a driving force makes a lot of sense.

If you disregard emissions for a second, a diesel with an auto makes complete sense for the daily commute, low rpms do good mpg, lots of easy low-down torque.

However, yes, emissions are a concern. It seems to me that not enough r and d has been done into a decent nox removal system.

Totally agree......

Revs = fuel consumption

Ignoring NoX...Diesels must be better as they consume for example half the fuel needed to cover the same miles as a petrol engine....so therefore half the emissions


My really revvy low geared 1.8 petrol Zafira MPV will only get 30mpg however i treat it.
But my C320CDI will get 45+ on a run and do it more safely because of the extra power at hand.

 

[grober]

It looks increasingly like high urban populations of people and motor vehicles are basically incompatible at a local level. Despite some obvious disadvantages it may be that electrically powered vehicles may be the answer in the short term if we wish to retain individual or family modes of transport in cities as opposed to public transport alternatives. Given the choice between a Smart Electric drive and a bus the Smart begins to look quite attractive?

 

[Deleted member 65149]

Just a couple of very high level articles. One is quite old now but has the basics. Emissions from petrol cars have been dramatically reduced by the introduction of catalytic converters, which oxidise pollutants such as CO to less harmful gases such as CO2. When compared to petrol cars without catalysts, catalyst cars have much lower CO, HC and NOx emissions, at the expense of CO2 emissions, which increase due to the oxidation of carbon monoxide to CO2. As a consequence of this, a catalyst car will also use slightly more fuel and become less efficient. However, despite these improvements, petrol cars with catalysts still produce more CO and HC than diesel cars, although exhaust emissions of NOx and particulates are much lower than diesel cars. In fact particulate emissions from petrol cars are so low that they are not routinely measured. Vehicle Emissions | Air Pollution | City Diesel | LPG | CNG HC - Hydrocarbons contribute to ground-level ozone formation leading to risk of damage to the human respiratory system. Some kinds of hydrocarbons, in addition, are both carcinogenic and indirect greenhouse gases. Cars and air pollution There are hundreds of documents out there that go into the detail of the damage that hydrocarbons do is greater to humans than NOx. Not going to spoon feed you for something that is out in the public domain. Take your head out of the sand and go and look. I can understand people not knowing this as its not been on the public agenda as the sensationalised story is about the global scandals and targets, but now you do, it is for you to go and do some research to educate yourself on the lack of knowledge you have on a topic you started. First though you have to admit to yourself that there is an issue her that you did not understand and that it may alter your beliefs when you do that research. There is no doubt that Diesels need cleaning up further, but when you take the human health element as you did, then you need to appreciate that certain petrol engines are actually worse. So, why do people still buy new large engined petrol cars when they are so bad for human health (even if they may be better for the environment)? And with that I will sign off from this thread as I can't see it going anywhere productive.

Thank you for those links. I had already seen them and was indeed going to quote from them, but as you rightly say one is quite old and neither clearly promotes diesel or petrol as being less harmful to health. The second link includes "Unlike the CO2 and fuel consumption figures, the figures for air quality pollutant emissions should not be used to directly compare different models of vehicle. The figures for these emissions are indicative rather than absolute, and emissions of them will vary between the same models" So we can't make any claims either way. I've made it abundantly clear that in no way do I defend the harmful emissions from petrol cars, yet you and a few others chose to ignore that.

You go on in your piece to say that "there are hundreds of documents out there that go into the detail of the damage that hydrocarbons do is greater to humans than NOx" From what I've read on that, the jury still appears to be out because of the difficulties in measuring both in the real world situation so comparisons aren't yet reliable. As you know, diesel and petrol both contain hydrocarbons, but in the past the greater efficiency of diesels resulted in less unburnt hydrocarbons. So yes, diesels used to produce far less. But guess what, petrol engines have also improved and they're now getting a lot closer to the efficiency of diesels, particularly those that employ direct injection. So the comparative hydrocarbon emissions argument is narrowing.

But what IS very clear from the latest evidence is that particulate matter is far higher from diesels than from petrol. That's why the diesel manufacturers have lobbied the regulatory authorities to significantly ease the diesel limits under Euro 6 for the next few years. The latest petrol engines already far exceed the standards.

 

[Deleted member 65149]

Totally agree...... Revs = fuel consumption Ignoring NoX...Diesels must be better as they consume for example half the fuel needed to cover the same miles as a petrol engine....so therefore half the emissions My really revvy low geared 1.8 petrol Zafira MPV will only get 30mpg however i treat it. But my C320CDI will get 45+ on a run and do it more safely because of the extra power at hand.

Things have moved on this century. My large engine petrol car that so many here want to bang on about does 40mpg and more on a run.

 

[190]

Much more recently I've witnessed first hand the negative impact of this obsession. I was the Community Governor at our local primary school and had to endure the ramifications of Ofsted. Seeing it all from the inside was frightening. Leading up to and during inspections the school went into meltdown to ensure that compliance were full in place.

I work in a school and we had Ofsted last week. It's a surreal and yes a frightening experience. But that's the society we live in where paperwork is valued and trusted more than people and values. If it's not written down then it doesn't happen or conversely if it is written down you must be doing it. Which of course is utter nonsense.

 

[David404]

but hydrogen as an I.C. fuel can only produce limited power because it too has it's own emission issues . I think this is currently the sticking point on its development.

Good point by Tim203. All to often the media (and state) have us looking at small parts of an issue so they gat to feel good whilst making others look bad. Hydrogen cars may look appealing in terms of the emissions they produce directly but that ignores the energy input (and resultant pollution) required to produce the Hydrogen fuel in the first place. There have been many reports of the pollution from factories producing solar cells, disposal and or recycling of batteries of all types presents environmental issues too and consumes energy, that in turn caused pollution. The Lithium in that rechargeable battery aint 'nice' stuff! And that's after we've extracted and refined the raw material in the first place.

What about car usage? How many families run 2 or more cars (my wife and I run just the one), how about the 'school run' typically short runs where engine efficiency (petrol and diesel) is at its lowest and pollutes around schools and young people. But then perhaps the kids are safer if you do the school run, lower risk of being involved in RTA.

Cars require raw material and energy to produce, another cause of pollution so shouldn't we seek to make them last longer...

Like all of life its a compromise and we trade one risk for another, pollution in one part of the life-cycle for another. To me its not clear that one (petrol or diesel) is is inherently better then the other. It is however obvious and entirely logical that we chase reduced emissions and greater efficiency from both.

 

[Deleted member 65149]

Thanks David and Shiny, it's good to read some grown up posts instead of wild accusations.

 

[Yugguy]

Thanks David and Shiny, it's good to read some grown up posts instead of wild accusations.

I'm cut to the quick.

 

[tangey]

Appears you missed answering this. (all that CO2 etc...)

I do ride a bike, and I walk a lot. So does my wife. That's why our only car covers an average of around 4000 miles a year. :success

That's a very personal subjective view of success. If you drove 4,500 would it still be success ? what about 9K, 15K. At what annual mileage beyond 4000 are you successfully not contributing to the death of young children ? (to use your argument)

 

[Deleted member 65149]

Appears you missed answering this. (all that CO2 etc...) That's a very personal subjective view of success. If you drove 4,500 would it still be success ? what about 9K, 15K. At what annual mileage beyond 4000 are you successfully not contributing to the death of young children ? (to use your argument)

Oh well, if you insist. My comment about riding a bike was in clear response to this:

Surely if emissions are such a worry, you would be driving a much smaller engine car / hybrid / EV or even better, riding a bicycle instead of going for the 350 petrol? :fail

I also said that I walk - a concept perhaps alien to some of you, but I'm sure you can google it in the same way I've been told to google things!

My closing ":success" was in direct contradiction to Litcan's ":fail". It simply meant that I WAS doing something in an attempt to cut down on harmful emissions. I did not claim some sort of tree-hugging superiority or whatever other crazy interpretation you may have chosen to confuse yourself with. The success was in succeeding to cut down on my car mileage, NOT success in eliminating world death. Therefore (I hope you're reading this carefully) there is absolutely no point whatsoever in responding to such a mindless, pointless and irrational question about "successful mileage". I only mentioned my family's total car mileage because I believe it to be far more environmentally friendly than any diesel car covering the average UK annual mileage. If you still can't understand that, I'll get my 18 month old daughter to explain it to you because she may be closer to your level of intellect.

I'm sorry to have to pick on you so personally like that, it's just the quantity of completely banal comments directed at me had finally reached a point that necessitated dropping to the same level. You just happened to be there at the wrong time.

 

[Yugguy]

Oooh you are awful, but I like it!

 

[Deleted member 65149]

I've just found a very interesting report by the DoT on road use statistics (https://www.gov.uk/government/uploa...ment_data/file/514912/road-use-statistics.pdf)

On page 38 it says that cars account for almost two thirds of road transport greenhouse gas emissions. That's far higher than I thought. On the same page is a graph showing million tonnes of CO2 equivalent by vehicle type between 2000 and 2014. Back in 2000 petrol cars were producing about five times that of diesel cars. By 2014 the levels had almost merged, although many of you will be delighted to hear that petrol cars were still producing slightly more. However, extrapolating the results to 2016 would start to reverse the trend. You'll also be saddened to hear that in 2014 only 36% of cars on the UK's roads were diesel. (https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/421337/vls-2014.pdf). So if 36% of cars produced nearly as much CO2 as the remaining 64% we have three possible conclusions: a) the millions spent on gathering all those statistics was wasted because the figures are wrong, or b) I've misinterpreted the figures (always possible), or c) diesel cars are producing roughly twice as much CO2 per car as petrol versions. Shocked? You should be. I can easily explain this apparent anomaly, but leave that up to you. I'll just say that the figures are correct.

 

[Dryce]

Ior c) diesel cars are producing roughly twice as much CO2 per car as petrol versions. Shocked?

Not shocking in any way as usage patterns vary - and people buying cars for high mileage will traditionally choose diesel.

Really it's CO2 per mile per passenger which is the important statistic.

I can't think of anybody I know who does company mileage with a petrol car - and those who have reasons to accumulate mileage for commuting or work or family almost all have diesels.

I'll just say that the figures are correct.

But without detailed context not necessarily very meaningful.

 

[Deleted member 65149]

Not shocking in any way as usage patterns vary - and people buying cars for high mileage will traditionally choose diesel. Really it's CO2 per mile per passenger which is the important statistic. I can't think of anybody I know who does company mileage with a petrol car - and those who have reasons to accumulate mileage for commuting or work or family almost all have diesels. But without detailed context not necessarily very meaningful.

Well done, you spotted the reason. But I don't agree that it's CO2 per mile per passenger that's the important statistic. If, as we're told, CO2 is the greenhouse gas that's killing the planet, then it's the total produced that's important. The "/mile /passenger" figure is useful in comparing cars as part of the purchase decision making process, and of course in saving money under the existing tax scheme, but that's pretty much it. Of course, making the wrong decision can influence the contribution to the overall figure if nothing else is done. But cutting down on mileage is likely to be more effective. And with petrol cars producing nearly as little CO2 per mile as diesel cars now, the individual choice is even less important for total levels.