[Closed] Changes to MOT, would this put you off buying a diesel?

<p>Depends, do you intend on maintaining the anti-pollution systems or just ignoring them then removing them when they inevitably break down as most seem to?</p>

I'll be putting our 2009 Golf (Diesel) through its MOT before 20th May just in case. This car has been great. 150,000 miles and going strong but I wouldn't buy another diesel because of the emissions but more so the fact that they will be priced/regulated off the roads if things carry on like this.  We're hoping to run the old Golf until EV's are a real viable option for a normal family.  When's that cheap Tesla landing in the UK?

I think the future will be tough for diesel owners in the next 5 years. They'll be the first type of fuel to be banned in city centres etc as electric vehicles become more viable (especially service vehicles)

"Depends, do you intend on maintaining the anti-pollution systems or just ignoring them then removing them when they inevitably break down as most seem to?"

MOT is also clamping down on that, any sign it's been tampered with is an automatic fail

There’s lots of other things that would put me off buying diesel waaaaaay before I got to MOT regulations. I wouldn’t touch one with a barge pole tbh.

I wouldn't throw any kind of money at a diesel - all signs are pointing to pricing/legislating them off the road, and quickly.

Crazy to think just a few years ago they were being promoted as the economical choice eh.

Sorry, all this diesel clampdown is all my fault. The first diesel I got immediately preceeded the clampdown.

To compensate you all, I'll put my winter tyres and mudguards on all my bikes. That should pretty much guarantee a lovely warm and dry spring.

Great news - all the horrible filth belching taxis will be off the streets in the next couple of years! Or maybe the taxi firms will all get their MOT's done by the local tame testers who will pass them with flying colours.

It's certainly a consideration.

It seems the knives are out for diesels at the moment and the more I learn about it, the more I'm inclined to see why.

I still have some holes in my knowledge, but as I understand it (please someone correct me if I'm wrong) the industry has been trying to make diesels cleaner for years and they have the diesels of 20 years ago poured soot from the exhaust

The last generation used DPF and the equally troublesome EGR to try to clean them up which I think greatly reduced the Co2 which is what we were taxed on in the UK, but had limited effect on Nox which is a really nasty thing to have coming out of the box you take your kids about in, but hey - we don't pay VED or BIK on Nox so who cares right? Well, everyone now.

Euro6 cars (true ones anyway) use Adblue which I *believe* does away with the DPF and EGR, this is the bit I'm not totally clear on so two things less to worry about?

I personally wouldn't rush to buy a non-Euro6 diesel, partly because we've been a bit blind to Nox in Britain and it's nasty stuff and partly because I think there's a huge amount of risk involved. At the moment Non-Euro4 cars/van are going to be banned from some cities, as sure as night follows day, euro4 cars will be next and no doubt euro5.

Euro6 cars produce no more Nox than equivalent Petrol cars, or so they say.

<p>Easy enough to knock the guts out a DPF or blank an EGR without leaving clues.</p>

I doubt it’ll have much effect, the new “guidelines” on the MOT.

There are too many vehicles older than say 5yrs that suffer with some blue smoke coming out of the exhaust, that new rule would take 70% off the road.. no chance.

bikebouy - my understanding are these are not guidelines, but the new standards.  All the details are on the gov.uk website. From 20th May all MOT test equipment will be updated with the new levels

but yes, i agree it does seem like a lot of fairly new cars will be failing, not sure how that will play with the public - wasn't that long ago we were all being led to buying diesel

really like the way modern diesels drive, feels like the manufactures have pumped loads of cash into developing ever more powerful and refined engines, and petrol has lagged behind somewhat

Anyway,

Diesel or Petrol, the answer is 'both'.

http://www2.mazda.com/en/next-generation/technology/

Very clever and competes with EVs on 'well to wheel' Co2 (based on current infrastructure)

Well with new diesel registrations down by 17% last year it’s encouraging to know that..

CO2 emissions from the average new car sold in the UK rose last year for the first time since 2000, according to an industry report, raising fears that the country will fail to meet its climate change targets as consumers buy bigger vehicles and turn against diesel.

Although motor manufacturers said new models coming on to the market were on average about 12% more fuel-efficient than their older versions, campaigners said a higher proportion of gas-guzzling vehicles leaving the forecourt had led to a 0.8% increase in the average amount of C02 generated per new car.

Falling consumer confidence has affected the lower end of the car market, with sales of the smallest, cheapest vehicle down by more than 10%.

So, just passing over from one nasty gas to another ..

If you're on top of servicing and pay attention to emissions gear then it shouldn't be an issue?

The best maintenance for any diesel is to be taken out every couple of weeks and driven in a spirited fashion (keeping the boost gauge high) for twenty minutes or so to trigger the DPF's regen mode.  EGR valves are a consumable part, but if the DPF is clogged then they'll soot up.

<p>EGR valves are NOT consumables, I swapped mine to quickly get it through it's MOT but the old one should clean up easily enough. So long as you catch it in good time or do preventative maintenance in the first place there's no reason why a valve shouldn't last the lifetime of the vehicle.</p><p></p><p>Agree on Italian tuneup where appropriate, if you have Eolys or such the DPF constantly regens.</p>

Mostly wrong pjay.

Egr has been around for a long time Euro 4 at least.

Then DPF to clean up particulates.

Then add SCR with urea to clean up NOx.

my current one has just failed on emissions

Is it a diesel?  Smoking?  Might be something like a MAF or boost pressure sensor - not too hard to fix.

Egr has been around for a long time Euro 4 at least.

Then DPF to clean up particulates.

Then add SCR with urea to clean up NOx.

Don't think he is wrong.  EGR is to lower combustion temperatures (along with changing injection timing afaik) which reduces NOx but also increases smoke.  The smoke then has to be filtered with a DPF.  I think that if you use AdBlue to remove the NOx you then don't need EGR an you can run hotter to increase efficiency and burn the smoke better.

So, do AdBlue equipped cars not have a DPF?  If they do they probably don't use them as much.

So, how hard is an engine swap to a petrol on a Galaxy?

<p>Probably hard enough that you would be cheaper just buying one with a petrol engine.</p>

do AdBlue equipped cars not have a DPF?

That's the bit I couldn't find info on - using google anyway - a lot of hits for "Adblue v DPF" which backed up my idea that you didn't need both, but I'm not sure where I got that idea in the first place.

<p>Dunno about Adblue but Eolys is used to lower the combustion temperature of the soot so it gets burnt off through general use, there is still a DPF in place to act as a filter but it's a passive rather than active system.</p>

Useful info ta - having a 2010 SMax that needed a bit of coaxing last year (OK, the tester told me to thrash it up and down the M3 for half an hour before bringing it in) - it's next ticket is due on Jun 8th. Do i get a calendar month or 28 days before hand? Will be booking it in early this year........

With AdBlue (assume Eloys is similar) there's a catalyst that reacts with the ammonia and the NOx to produce nitrogen and water:

2NO + 2NH3 + ½O2 -> 2N2 + 3H2O

3NO2 + 4NH3 + 3O2-> 7/2N2 + 6H20

Yes

Staggered that a 7yo car may be at its end of life. Makes you realise how countries like Framce which only test every two years have it much more easily

@ply hard to see how they could ban all diesels - my wifes 11yo micra has same emissions rating as a new 2tdi Euro 6 (using French “CritAir” stickers)

What happened to running Diesels on chip fat?

Seriously, why did this never take off? is there an actual reason or is it just because fuel companies don't like it?

Also are there any retro fit things that can improve the emissions of Diesel cars, like a 2008 SMax....

Among the changes will be one that if the “exhaust on a vehicle fitted with a diesel particulate filter emits visible smoke of any colour” the car will be issued a Major fault.

Does that mean that my 20 year old Toyota camper which I'm pretty sure has no filter, is exempt from this?

What happened to running Diesels on chip fat?

Couple of issues - it's harder to get it to work without risks in a modern engine, but the real reason is that as soon as the government made fuel manufacturers put 5% biodiesel in their diesel, used chip fat suddenly had value.  So instead of restaurants paying to have it taken away, they sold it to people who refined it and sold it on to fuel manufacturers.  So you couldn't pick it up for free any more.

McDonalds now use all their used chip fat in their own fleet - according to the slogans on the lorries that is.

I'm also keen to know that BillOddie.  My 2008 Golf has plenty of life left in it and is one of the last models without a DPF.  I'm hoping that means this means it falls outside of this change.

“exhaust on a vehicle fitted with a diesel particulate filter emits visible smoke of any colour”

Is this a "visual" check by the MOT tester?

If so thats open to so much interpretation to make it nul and void a requirement..

One mans Blue is another mans Black..

@ Molgrips, that's kind of what I thought. If it was made freely available or some other variant, rather than used chip fat, would the world be a better place? And would I get more miles out of a chip fat diesel than an electric car and still be able to carry loads of camping gear and bikes???

They won't have tens of thousands of cars suddenly irredeemably fail an MOT now will they?  That would cause chaos.

If it was made freely available or some other variant, rather than used chip fat, would the world be a better place?

Free fuel?

All fuel has a cost - even used chip fat takes energy and other materials to refine.  Lots of possible sources of biofuel take a different toll on the environment.

As for camping trips - someone will be along with an electric range extended van soon enough.

The MOT testers will know that older cars don't have DPFs, so they won't be looking for signs of "interference".   They will still check that the emissions are within limits. Assuming that you have a 1999 Pug 405 then the emissions should be in line with the govt max levels and the levels associated with that individual engine.

If they really want to clean the air in cities they should look at buses, coaches and trucks.

Also shipping is notoriously bad. The stat is something like the 10 biggest container ships in the world pollute more than all the cars, motorbikes, vans, trucks and buses in the entire world. Depressing.

Londons ULEZ looks to change or toughen up the rules about pollutants from vehicles in the city, and the scope has been widened out to include "inside the M25" and "inside the North and South Circular" zones..(the T-Zone)

Khan has changed and brought forward some of the original changes proposed to make it more stringent a regime. And Busses/Trucks/Taxis are included within that new scope (to what extent I don't know).

Hybrids are no longer exempt, they are charged the ULED like everyone else, and when ULEZ comes in PHEV's will be charged.. too it'll be only Pure Electric vehicles that are exempt.

And 2019 isn't that far away now..

Free fuel?

No, no I just mean a readily available fuel source similar to chip fat that doesn't produce the bad shit that diesel does. It seems like we had an answer years ago but chose not to use it. I just wonder why exactly. There must be a reason other wise why would be pissing about with electric?

The Adblu v EGR was a truck thing.

To meet Euro 4 and 5, where the big clamp down was NOx, the limits could be met with either EGR, or Adblu. EGR worked by lowering combustion temperatures, resulting in a bit more smoke, and the use of an oxidising catalyst. It also increased fuel consumption due to the lower combustion efficiency, and needing more cooling due to the EGR cooler. Adblu allowed combustion temperatures to remain at their optimum, and the SCR and Adblu handled the NOx.
Nearly all truck manufacturers opted for AdBlu on fuel economy grounds, as the cost was quickly offset by fuel savings. IIRC it was around 4-5%, so even after you factored in the ongoing cost of the SCR system, it was the cheaper overall system.

Cars/light vehicles always opted for EGR, as it was a cheaper option to implement, and the reduced fuel consumption was mitigated by improving fuel injection.

For Euro 6, all technologies are needed. EGR helps control combustion temperatures to keep them in their optimum range, an oxidisation cat helps reduce soot before it hits the DPF (they're usually combined into one unit)then the SCR system handles NOx.

In terms of reliability, provided you're doing reasonable length journeys regularly, chances are you won't have any major problems. The system takes care of itself, it's only when you do endless short journeys and ignore warnings, that you're likely to have clogging problems. Modern DPF systems will regenerate in under 15 minutes from cold, provided the vehicle is being driven and not just stuck in traffic, but even in traffic they can normally maintain a regen.

PSA engines with the Eolys system, don't continually regen. The Eolys is a chemical that dopes the fuel tank, that makes regens quicker (IIRC it makes the soot easier to burn off, so regens don't have to be as hot).

Also shipping is notoriously bad. The stat is something like the 10 biggest container ships in the world pollute more than all the cars, motorbikes, vans, trucks and buses in the entire world. Depressing.

What sort of pollution? Greenhouse gases, or poisons like NOx? If the latter, then it's lucky they don't hang around inner city schools. If greenhouse gases, then that's a problem, but it's worth remembering that the reason air travel is so polluting is because the pollution is in a place where it is much more harmful, rather than the absolute quantity.

Ships can run on different grades of fuel and will use one (more refined, less polluting) type in e.g. the Channel, then switch to the crude stuff when through the Western Approaches. If they are caught using the crude stuff in the Channel they get fined.

<span style="display: inline !important; float: none; background-color: transparent; color: #222222; font-family: 'Open Sans'; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; line-height: 22.4px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">No, no I just mean a readily available fuel source similar to chip fat that doesn’t produce the bad shit that diesel does. It seems like we had an answer years ago but chose not to use it. I just wonder why exactly. There must be a reason other wise why would be pissing about with electric?</span>

Er, it still produces the "bad shit". At the end of the day you're still burning oil, producing CO2, NOx and particulates.

Adding biodiesel to conventional diesel was primarily a move to reduce reliance on fossil fuels, not really anything to do with pollution concerns. However it was found the biodiesel helped with the lubricity problems caused by the removal of sulphur, but did introduce some problems as in high pressure systems it can breakdown causing sludge problems (certain trucks were notorious for it).
The EU stopped their plans to gradually increase the minimum require biodiesel requirement, as it was having too big an effect on food production.

No, no I just mean a readily available fuel source similar to chip fat that doesn’t produce the bad shit that diesel does. It seems like we had an answer years ago but chose not to use it.

What did we have years ago?  Are you referring to chip fat?  Cos there was never anywhere near enough of that compared to diesel!  And we do use it all afaik for fuel.  It's mixed with our regular diesel.

Yeah, just wondered why we didn't go more for the biofuels, not necessarily used chip fat but proper stuff manufactured to replace diesel but it seem mc answered me with some science.

Yeah, just wondered why we didn’t go more for the biofuels, not necessarily used chip fat but proper stuff manufactured to replace diesel but it seem mc answered me with some science.

For a while we were growing Rapeseed for Oil and mixing it into normal crude based diesel, but I think it was causing some problems with some fuel pumps - for a little while you'd see warning on the inside of caps on cars with words like "no more than 5% bio fuel" or the like and warnings on pumps if you knew where to look, I'm not sure it still goes on.

Anyway, since then cooking oil in supermarkets anyway has jumped to about the same price per litre at diesel and I once read that if we wanted to replace all our current diesel with bio diesel there's not enough extra agricultural land to produce it all globally.

Equally, supposedly there's not enough lithium globally to replace all cars with EV nor enough electricity production to charge them all.

There's no way to refine hydrogen efficiently enough to replace all cars with Fuel Cells, nor again enough power stations to refine the hydrogen.

mc beat me to the explanation (and gave a better one than I could be bothered to give).

The SCR vs EGR thing was way back (you could achieve Euro 4 or 5 NOx levels with either strategy).

I run hot vibration durability and fatigue tests of (mostly truck) exhaust systems. Euro 6 definitely has both DPF and SCR. The detail of current EGR may be different to what they did pre-SCR but may still be there to some extent.

Some truck exhaust systems are massive - maybe plus 200kg and the size of a big fuel tank. Some companies called them "EGPs" (Exhaust Gas Processors) because they were essentially mini chemical processing plants.

And going back to the op I wouldn't be bothered about the MOT - a properly maintained and functioning system will pass (working DPF = no smoke). I presume the new laws are to give some teeth to catch the cut out and reweld DPF crew.

What car do you have that is currently struggling to pass the MOT? My (Euro 4 I think) EGR but non-DPF 1.6 HDI with 100,000 miles and 10 years barely registers on the smoke reading.

Probably going to keep hold of it for a few more years to see how everything pans out petrol vs diesel vs electric vs hybrid.

Yeah, just wondered why we didn’t go more for the biofuels

Cost - it's hugely expensive to grow and harvest fuel instead of just pulling it out of the ground in huge quantities.  Also remember that crude oil is refined to produce a huge range of valuable things - rapeseed oil is just for motor fuel.

The other more problematic point is that when you use good arable land for fuel so you can drive to a trail centre on a weekend, it's not being used to grow food that a family can eat.  In the US the corn farmers are happy to have corn made into ethanol for fuel cos it makes their crop more valuable.  But this drives up the price so that then corn farmers in Mexico sell it to the US for fuel instead of to poor Mexicans to eat.

Also shipping is notoriously bad. The stat is something like the 10 biggest container ships in the world pollute more than all the cars, motorbikes, vans, trucks and buses in the entire world. Depressing.

You need to be careful with your daily wail headlines!  Firstly the stat is the 16 biggest container ships in the world (not 10) - but also they don't "pollute more than" - which would suggest all pollutants - but their sulfur emissions are as much as all the cars in the world (second bit of exagerations there - only the cares not the busses or trucks) - but their CO2, NOx etc are not . comparable.  I'm not saying it is something to celebrate - but equally don't trick yourself into believe cars are not a major part of the problem.

This massive u-turn on promoting diesel as the way forward for personal mobility. Anything to do with the mahoosive investment Saudi Arabia have made in their diesel production by any chance?

We can quote all that the scientists say about pollutants but who funds the research? Might that be western governments who need to wrestle control of oil supply from an area that really don't like western influence?

Perhaps by reducing Saudi oil revenues, the west think they can exert pressure on them to toe the line? Only a fool repeatedly bangs their head against the wall expecting a different result...

Slackalice, have you been smoking what Jivehoneyjive smokes?

The u-turn is because of changing science.  New stuff has come to light.  Are you suggesting you would not expect to change policy in response to new science?  Or are you calling all scientists bent for no reason?

Hmm, I'm about to dump a smoky Euro4 galaxy, choice is Volvo D3 engine or Hyundai 1.7cdti..... Should I?

I'm not calling scientists bent! Do some reading into the issues in the area we know as the Middle East from the mid C20th to date.

Anglo Persian oil company, the USSR, the USA and particularly the British have tried again and again to regain control of the oil production and supply from this region. Again and again, the countries involved have objected to the exploitation (OPEC), again and again, the countries wanting to secure supply have supported one government and another with arms and munitions, often supplying rebel forces to overthrow an incumbent administration only to find the successors even more opposed to supplying the west with the black gold.

Iran, the Shah and Khomeini, Iraq and Saddam Hussain, to name two, there are plenty more.

Surveys and research will always support those who fund them, statistics are like that, easily manipulated.

I dont dispute the pollutants, what I'm suggesting is that there is more to this than the simple let's look after the planet. Those in power don't give a **** about the planet, all they give a **** about is their own personal wealth

EDIT: Don't believe the immediate 'truth' being given to you...

Ah this makes sense.  I had an MOT last Thursday and had a Smoke Test certificate handed to me.  It may have had them before, but I hadn't remembered it.

0.43 is the opacity value.  Is that good?

BioDiesel has negative side effects, not quite cutting down the Borneo rainforest to grow for Palm Oil but negative none the less

All a nightmare really, I have only ever bought 1 diesel car but its quite hard to buy some used car models and nkt go diesel as petrol varients are rare or non-existant.

Friends have a very nice A5 with “that” VW 2tdi engine and they have had zero interest on Autotrader despite a decent price. How VW have got off the hook in UK/Europe is a disgrace

I reckon my van is screwed come next MOT.

I think if you're doing a reasonable mileage, with plenty of long runs then diesel is always going to be hard to beat. The only risk as I see it is relatively higher increases in fuel duty on Diesel in the future.

Think of changing my 2002 Audi A6 1.9tdi in for a newer 2011 diesel. I’m doing under 10k a year and mostly only use it at weekends on the motorway.

Would I be better off considering a petrol engine considering the bad press on diesels?

Update: after some jiggery pokery my car has squeaked through its mot

question still remains as too next car choice, short term I'm going to wait and see how the new mot standard impacts the pass rates

on a positive note, the delay in car buying brings forward bike buying! New job means I can commute by bike two or three days a week... so whatever car I buy it will get less use (that probably means a petrol is the smart choice)

Using a diesel less is not the issue - using it for short trips is the issue.

>ads678

Yeah, just wondered why we didn’t go more for the biofuels, not necessarily used chip fat but proper stuff manufactured to replace diesel but it seem mc answered me with some science.

The reason (or another reason) bio diesel didn't make it as a fuel source was the move to common rail injection. Around 1997 diesel engine design changed to be more like petrol engines in that they atomized the fuel at very high pressure before combustion. Vegetable oil was unsuitable or less suitable for this than straight diesel.

Tinfoil hat time - I had a lengthy rant on here a long time ago about this and how performance gains in diesels seemed negligible, or certainly not that great. Perhaps common rail was invented to make diesels cleaner, perhaps it was to make them more powerful, I don't know but I don't really understand or see any huge performance benefits. Older diesels like my Hilux still run fine on straight vegetable oil.

jimjam, your hilux won't manage 80+bhp per litre though.

Common rail injection made a huge difference to diesels, as it allowed multi-stage injection, and far finer atomisation. Which translated to smoother running, cleaner burn, and the ability to get more power for less soot.

Around 1997 diesel engine design changed to be more like petrol engines in that they atomized the fuel at very high pressure before combustion. Vegetable oil was unsuitable or less suitable for this than straight diesel.

It's my understanding that whilst veg oil could be used it requires heating.  Biodiesel on the other hand is fine.  The big issue is with DPFs and active regen resulting in unburned oil coating the cylinder walls, ending up in the sump then eventually polymerising turning your engine oil in to jelly.

The big advantage of common rail diesels is the ability to vary injection timing arbitrarily - and have multi stage injection.  So you can make it run more quietly and smoothly under light load.  VW PD engines (like mine) have higher injection pressure than CR but they can only inject over a narrow range of timings.  The old mechanical PD engines had essentially no timing adjustment which is why you'd get a huge lump of torque all at once then nothing.

CR also allows fuel to be injected in the exhaust stroke to pass hydrocarbons to the catalyst in the DPF to heat it up enough to burn the ash off.  Also not very possible without CR.  It definitely made them more efficient.  I had an old school VW TD engine for a while with mechanical indirect injection which would run briliantly on veg oil.  Only did about 45mpg though as compared to 62mpg or so in the PD, and it was noisy as hell.  The PD engine has 50% more HP too.  And CR are even better still.

No.

Reason being the new vehicle will not even register on the machine.

Just had my 14 plate VW engined car MOT'd by an old work college and it was reading zero. I didn't think Euro 6 was fitted to cars, only Commercial vehicles? Could be wrong on that one.

Anyway my car would only free rev to 2.5k and the reading was zero. My tester also told me that they no longer bother testing the newer Wagons as its a waste of time. As an ex tester myself I see his point and he had no reason to lie to me.

Typical media hysteria.

<div class="bbp-reply-author">mc
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jimjam, your hilux won’t manage 80+bhp per litre though.

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Well no but my point was old diesels will run on anything.

It’s my understanding that whilst veg oil could be used it requires heating. Biodiesel on the other hand is fine. The big issue is with DPFs and active regen resulting in unburned oil coating the cylinder walls, ending up in the sump then eventually polymerising turning your engine oil in to jelly.

Heating isn't a big issue, you can buy inline fuel heaters to adapt older diesel to run on straight vegetable oil if you live in colder climates.

CR also allows fuel to be injected in the exhaust stroke to pass hydrocarbons to the catalyst in the DPF to heat it up enough to burn the ash off. Also not very possible without CR. It definitely made them more efficient. I had an old school VW TD engine for a while with mechanical indirect injection which would run briliantly on veg oil. Only did about 45mpg though as compared to 62mpg or so in the PD, and it was noisy as hell. The PD engine has 50% more HP too. And CR are even better still.

I'm not denying that CR was an improvement. Apologies as I'm not going to google this to back it up, but iirc the first generation CR engines didn't really show any great improvement over the generation of tdi engines they replaced. Example, Toyota replaced the 2.4 tdi in the Hilux with the 2.4 d4d, producing almost exactly the same power and torque. And there were other similar examples. Yes they may have evolved over time to the point where today, 20 years on, they are significantly more powerful, more refined and more efficient but with the exception of heavy duty applications there's a petrol engine that will do the job better.

I feel as though engineering common rail egr dpf adblue diesels to make clean efficient diesels was an evolutionary dead end that could have been solved by cutting tax on petrol.

Hilux with the 2.4 d4d, producing almost exactly the same power and torque. And there were other similar examples.

But what about economy and emissions?  They can more or less choose they power they want - they choose the power levels according to what the market wants, not what's technically possible.  That's why you had VW TDIs of the same size with 140 and 170 and now 150 and 180 bhp.  They just chose to fit smaller or larger turbos and injectors and charged more for them.

I feel as though engineering common rail egr dpf adblue diesels to make clean efficient diesels was an evolutionary dead end

Don't think so.  It's allowing diesel engines to get the full potential from the fuel without the pollutants. Nice idea, a much better one than EGR.

But I reckon plug in hybrids are the way to go in the short term.  Or range extended EVs.  The tech exists now, and with plugins the batteries are small enough that supply should be less of an issue.

But what about economy and emissions? They can more or less choose they power they want – they choose the power levels according to what the market wants, not what’s technically possible.

Yes but the upshot slight increase in economy, less co2, but more dangerous particulates. Take a Skoda Superb as a suitably bland example. 2001 PD engine 2.0 tdi, 140bhp, 236lbs ft . Same year 2.8 petrol engine 196bhp, 207lbs ft. Fast forward almost 20 years and the 2.0 tdi still produces 140bhp, 250lbs ft. It produces less bhp, and is slower 0-60 than a 20 year old normally aspirated petrol engine.

Yes the diesels are more fuel efficient but they are still heavy smelly engines that belch out soot and particulates. What was the net gain in tax breaks to get everyone into diesels to then suddenly start to tax them out of them?

I've never owned a diesel and most likely never will so the question the OP posed doesn't really apply to me.

But I do use a few hire cars through work and have noticed that we only get petrols now over the last few months.  We always ask for a diesel as we can fill the tanks up from our delivery van/truck pumps avoiding the £2/ltr charge for refuelling but each time now since the hire co got a new fleet we've been told there aren't any available (talking cars up to the size of a Focus/small SUV's etc).  If this is happening across the majority of hire fleets then that will impact what cars are available at the car supermarkets on a year or so, this will drive the switch away from diesel more than anything I think.

DEFRA have stopped ordering diesel cars of any kind.

The EGR failed at 160,000 miles on my 2015.  Replaced for <£300 (with labour at indy)

Passed MOT 2 weeks ago with no advisories.

Nearly all my journeys are 25+ miles.... most use is way longer so no real wish to change.

Fast forward almost 20 years and the 2.0 tdi still produces 140bhp, 250lbs ft. It produces less bhp, and is slower 0-60 than a 20 year old normally aspirated petrol engine.

Not sure you appreciate what's happening here.  The TDI produces 140bhp because that's all they want it to produce.  It's NOT because that's the maximum of which it's capable.  They've just increased the economy.  The marketers have decided 140 is a sensible amount, so that's where it stays.  People who buy large petrol engines on the other hand don't care about economy, so they have been increasing the power steadily.

And you can't compare a 2.8 petrol with a 2.0 TDI, they're created for totally different purposes and sold to different people.  This is not a technological issue.

What was the net gain in tax breaks to get everyone into diesels to then suddenly start to tax them out of them?

You know they still emit less CO2 don't you?  And in any case - diesel didnt' get a tax break - low CO2 got a tax break.  The lowest still being petrol hybrid.  I feel your rant lacks focus somehow 🙂

If you read past the headlines and read the actual guidance its clear they are targeting remappers and EGR/DPF deleters. Theres gonna be alot of VAG cars failing mot on emissions with their remaps.

even buying 3 years old now your buying euro 6 ... youll be grand till the end of the cars life im sure.

what i wouldn't buy now is a NEW diesel car - or anything post april 2017.. - they are the ones that are going to face the biggest tax increases quickest under the new regime.

Its all good and well saying ill buy petrol ill buy hybrid.

i went out with that mindset.

once i narrowed it down the cars that fitted my needs and went out to buy a petrol.

I was left with a choice of a 1.2 puretech that is noisy,vibrates like a lumbering v8 at idle and did not even get close to advertised economy..... think low 30s rather than 55mpg advertised. - or a 1.6 old style petrol.... which due to high emissions was also in the higher tax bracket and still only did 40mpg....

Worse still if i wanted either i had to buy NEW - even nationally there were none for sale in the 3-5 year old market.

MY next car im sure will be hybrid im sure but thats a while off.

molgrips

Not sure you appreciate what’s happening here. The TDI produces 140bhp because that’s all they want it to produce. It’s NOT because that’s the maximum of which it’s capable. They’ve just increased the economy. The marketers have decided 140 is a sensible amount, so that’s where it stays. People who buy large petrol engines on the other hand don’t care about economy, so they have been increasing the power steadily.

Molgrips, I've noticed that whenever you're debating, whether it's intentional or not you regularly suggest that your sparring partner doesn't understand your argument or point of view. I completely understand the point that engines come in different states of tune and that 140bhp is not the maximum possible bhp for a 2.0 tdi but it's moot to my point because prior to common rail, turbo diesels weren't in their maximum state of tune, nor is any production petrol engine.

In 20 years vag went from a pd turbo diesel that produced 140bhp and 173 g/km to a CR making 140bhp and 117 g/km. But we know that the test is completely unrepresentative of real world driving conditions and that manufacturers cheated the tests so what what are those figures worth?

And you can’t compare a 2.8 petrol with a 2.0 TDI, they’re created for totally different purposes and sold to different people. This is not a technological issue.

They are sold to different people because they've been marketed to different people and that's targeted based on the fact that there's 60p per litre tax on petrol and the ved was designed to incentivise people to buy diesels. Everywhere else in the world a 3.0 petrol engine is a perfectly normal generic, basic standard engine to put in a 5 door saloon car. We've been conditioned to think they are some kind of sexy high performance toy because of punitive taxes.

You know they still emit less CO2 don’t you? And in any case – diesel didnt’ get a tax break – low CO2 got a tax break. The lowest still being petrol hybrid. I feel your rant lacks focus somehow

Diesels did effectively get a tax break because co2 alone was targeted. I  agree, perhaps my rant isn't consistent, perhaps I'm argueing too many points or trying to join up too many dots but we don't know where vegetable oil fueled turbo diesels could have gotten to because manufacturers shut down that line of inquiry chasing pointless metrics that incentivized them to build cars that met unrealistic tests and still poisoned us. Now the public is cottoning on to what manufacturers likely knew all along, so now we have to ditch diesels and buy petrol hybrids. If they'd incentivized people 20 years ago to buy petrols and developed petrol engines to their optimal potential we wouldn't be having this discussion.

The buying public in Europe have been piggy in the middle here while legislators and manufacturers pissed about and made up the rules as they went along.

So is buying a used 6 year old (2012) diesel still a wise idea? Need to change my car this year. Currently looking at VW Passat 2lt CR diesel estate

Everywhere else in the world a 3.0 petrol engine is a perfectly normal generic, basic standard engine to put in a 5 door saloon car.

I'm really not sure that's true at all.  I've certainly never been anywhere that's the case.  It's not the case in the USA even.  Such things are certainly more common, but the days of big NA V8s and four speed autos are gone.

But a 3.0 petrol engine is for people who want to go fast and don't care about fuel.  A 2.0 TDI is for people who do care about fuel and want to go just fast enough.  You cannot ignore the fact that a 3.0 petrol emits much more CO2 than a TDI.  CO2 is still important, as NOx is.

If they’d incentivized people 20 years ago to buy petrols and developed petrol engines to their optimal potential

But they have been developed greatly in recent years.  The small eco-boost type petrol engines, they are a huge advance.  The amount of engineering in those is comparable (or greater) than a typical diesel, for better or worse. My Dad's Golf had an air/water intercooler for example you don't get those on standard diesels.

Re the development of diesel - that started in the 70s oil crisis.  VW's initial white paper was published in something like 1977 where they set out their goal to develop passenger diesel cars.

we don’t know where vegetable oil fueled turbo diesels could have gotten to because manufacturers shut down that line of inquiry chasing pointless metrics that incentivized them to build cars that met unrealistic tests and still poisoned us.

I disagree.  Veg oil for fuel is simply not an option and never will be - nothing to do with technology, it's to do with the supply of fuel.  We can't grow enough oil seed rape, nowhere near.  People are working on other sources of biofuel, and yes I agree that it needs much more investment.  But it's not really a car company issue since the fuels will work in most engines with a little tweaking.  The technology to use such fuels anyway certainly isn't an issue - the technology to create them is.

So is buying a used 6 year old (2012) diesel still a wise idea? Need to change my car this year. Currently looking at VW Passat 2lt CR diesel estate

I'm in the same boat, I have an 05 diesel which sails through MOT's and is a lovely engine, but the interior and body work have seen much better days.

I think it might be possible to get a better deal with all this negative press and misunderstanding of what it means!

So is buying a used 6 year old (2012) diesel still a wise idea? Need to change my car this year. Currently looking at VW Passat 2lt CR diesel estate

I’m in the same boat, I have an 05 diesel which sails through MOT’s and is a lovely engine, but the interior and body work have seen much better days.

I think it might be possible to get a better deal with all this negative press and misunderstanding of what it means!

Before xmas I bought a 2013 VAG turbo diesel. As a 4 year old car it was £2000 cheaper than the equivalent petrol version of the same car (with similar kit and mileage)

To sell/trade in in 5+ years either car will be worth less than £2000 total, regardless of emission regulations, so my dirty diesel might lose me a couple of hundred at this point. (net saving approx £1800).

For the next 5 years I'll enjoy £20/year tax (or slightly more if they bump the rate, but they never retrospectively change tax band) along with 60mpg hwy 50mpg city. Car handles well and does 8.0 secs 0-60.

Annual saving on fuel and tax = several hundred over equivalent petrol.

On the environmental issue, car already exists and is too young to be realistically scrapped, therefore someone will be driving it for the next 5 years, may as well be me.

So is buying a used 6 year old (2012) diesel still a wise idea? Need to change my car this year. Currently looking at VW Passat 2lt CR diesel estate

I would say buying a VW isn't a wise idea, never mind the diesel issue. I still have no idea why people flock to VAG group cars.

I  agree, perhaps my rant isn’t consistent, perhaps I’m argueing too many points or trying to join up too many dots but we don’t know where vegetable oil fueled turbo diesels could have gotten to because manufacturers shut down that line of inquiry chasing pointless metrics that incentivized them to build cars that met unrealistic tests and still poisoned us. Now the public is cottoning on to what manufacturers likely knew all along, so now we have to ditch diesels and buy petrol hybrids. If they’d incentivized people 20 years ago to buy petrols and developed petrol engines to their optimal potential we wouldn’t be having this discussion.

The manufacturers really don't care what fuel so long as they are on a level playing field or better still one tilted towards them.

Vegetable oils are not intrinsically cleaner than diesel and as pointed out they diesels are not specifically cleaner than petrol...its all a matter of how they are designed and also how they are used

My mother used to have a tiny little Fiat 500 ... over 300 miles on a motorway it would burn a litre of engine oil...  all of that is spat out with no EGR and no DPF... my diesel goes 12,000 miles between services without topping up the engine oil, let alone a litre!  The volume of fuel burned is not dissimilar.

I can't see any way a car burning 1L of engine oil can be producing less pollution than my diesel on the same trip.

Anyway, the manufacturers just want to sell cars.... they will sell the ones that legislation makes most attractive.

molgrips

I’m really not sure that’s true at all. I’ve certainly never been anywhere that’s the case. It’s not the case in the USA even. Such things are certainly more common, but the days of big NA V8s and four speed autos are gone.

Go on Autotrader usa and take a look. If you search for a diesel ford all you'll see is pages and pages of giant pickup trucks. You can search by cylinders and again you'll see that 6 and 8 cylinder engines outnumber 4 cylinders hugely. For example 4 cylinder Audi returns two pages. 6 or more cylinder Audi (petrol) returns 12 pages. You couldn't even buy a 1.0 ecoboost focus there till last year but we've had them since 2010 or 2011.

But a 3.0 petrol engine is for people who want to go fast and don’t care about fuel. A 2.0 TDI is for people who do care about fuel and want to go just fast enough. You cannot ignore the fact that a 3.0 petrol emits much more CO2 than a TDI.

No a 4.0 or 5.0 or 6.0 petrol engine is for people who want to go fast. A 3.0 petrol engine is for people who can't afford a V8.

CO2 is still important, as NOx is.

Now it is. Nox didn't seem to be an issue to the public until 5 or 6 years ago.

 The small eco-boost type petrol engines, they are a huge advance. The amount of engineering in those is comparable (or greater) than a typical diesel, for better or worse. My Dad’s Golf had an air/water intercooler for example you don’t get those on standard diesels.

I've been raving about them for must be four years (I've owned one for three). Every time I brought it up three years ago people (including you) instantly poo-poo'd the idea because look, I can get 65+ mpg out of my ancient diesel. Why did manufacturers suddenly start investing in small capacity petrol engines though? Why didn't they just spend that money on diesels? What did they see that led them down the development path toward microscopic petrol engines with variable geometry low intertia turbos? I'm cynical.

I disagree. Veg oil for fuel is simply not an option and never will be – nothing to do with technology, it’s to do with the supply of fuel. We can’t grow enough oil seed rape, nowhere near. People are working on other sources of biofuel, and yes I agree that it needs much more investment. But it’s not really a car company issue since the fuels will work in most engines with a little tweaking.

Can't supply everyone with veg but what if was just for a certain sector of the market? Perhaps supply wouldn't be an issue if diesels were limited to appropriate applications (lorrys, vans, trucks, boats) and much more suitable petrol engines had been favoured in small passenger cars instead of being taxed out.

Can’t supply everyone with veg but what if was just for a certain sector of the market?

Why would you want to?

Perhaps supply wouldn’t be an issue if diesels were limited to appropriate applications (lorrys, vans, trucks, boats)

Those are types of vehicles not applications as such.

Diesel is applicable to towing heavy loads and coating on motorways

and much more suitable petrol engines had been favoured in small passenger cars instead of being taxed out.

Petrol is more suitable for light loads and short journeys and urban driving

Not using a car is even better

The problem is that the legislation mis-sold cars or drive the mis-sale of cars.

My own diesel car is far more eco-friendly than a tiny petrol car for short journeys ... because I use a bike.  If I intended driving less than a few miles on any regular basis I'd get a small petrol or electric but its perhaps once a month I do less than 25-50 miles.

My main concern is I just don't want to be spending £6- £7K on a car that I'm going to struggle to sell if I ever need to change it.

I am loving the VW UP GTI. It's the only thing that would tempt me away from a diesel car.