Should I buy used diesel rated with EU 5 emission?
Should I buy used diesel rated with EU 5 emission?
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Discussion

Natjack

Original Poster:

9 posts

95 months

Thursday 1st March 2018
quotequote all
Hello,

I am looking for advice from diesel engine and regulations experts please.

I have found a 64 plate diesel SUV that I would like to buy, however am concerned about its EU 5 emissions rating and what this will be in the near future.

I'm conscious of the new restrictions being brought in around the country for certain types and ages of diesel cars and want to understand if EU 5 is likely to be penalised in the same way. Ultimately - I want to future proof my car as I hope to have it for up to 10 years.

The 65 plate model of the same vehicle is EU 6, which I am assuming is much less likely to suffer issues in the near future, but it's quite a bit more expensive than the 64 plate.

As we are looking at an Audi, we know that they were caught up quite heavily in the emissions scandal - hence our concerns...

I've done some research around the topic, but there isn't anything conclusive that I can find, so any insider knowledge or expert advice would be very welcome.

Thank you


Benrad

653 posts

170 months

Thursday 1st March 2018
quotequote all
In the real world the EU6 car will have much lower emissions

EU5 and before might be banned from, or charged to enter, city centres and urban areas. So might EU6, but it's less likely

I doubt either car will be banned outright, I don't think they can increase VED rates but I could be wrong. I suspect they'll rely on increasing cost of fuel to get ICE vehicles off the roads without resorting to banning them.

It's all guess work though, I work in diesel engine development for performance and emissions, but in heavy duty rather than passenger car

Natjack

Original Poster:

9 posts

95 months

Thursday 1st March 2018
quotequote all
Thank you. Would you buy (or recommend to someone you know) a 64 (EU5) plate diesel car with your knowledge in the field?

Wooda80

1,743 posts

96 months

Thursday 1st March 2018
quotequote all
What you are asking is if anyone knows what government policy will be regarding the taxation of diesel cars over the next 10 years that you plan to own it.

And the simple answer is that no, no one knows what that is likely to be. No one knows who will be in government for the major part of the next 10 years, never mind what they may be thinking now or what pressures may come to bear in say 6 or 7 years time.

What would be a fair assumption however is that whilst taxes like VED are likely to increase rather than stay the same or decrease, and whilst there will undoubtedly be steps to reduce the number of private cars in city centres ( regardless of how they are powered ) no government is likely to implement radical tax increases in VED that will suddenly make large numbers of existing cars uneconomical to run - it would be far too unpopular.

The Euro VI car that you are looking at will likely have slightly better CO2 and significantly better NOx emissions than the Euro V. As with any car purchase, buy the newest, lowest mileage example that you can afford and if that is a Euro V then so be it. There's no point in spending money you don't have to try and second guess a government policy that can't be predicted.

Natjack

Original Poster:

9 posts

95 months

Thursday 1st March 2018
quotequote all
Wooda80 said:
What you are asking is if anyone knows what government policy will be regarding the taxation of diesel cars over the next 10 years that you plan to own it.

And the simple answer is that no, no one knows what that is likely to be. No one knows who will be in government for the major part of the next 10 years, never mind what they may be thinking now or what pressures may come to bear in say 6 or 7 years time.

What would be a fair assumption however is that whilst taxes like VED are likely to increase rather than stay the same or decrease, and whilst there will undoubtedly be steps to reduce the number of private cars in city centres ( regardless of how they are powered ) no government is likely to implement radical tax increases in VED that will suddenly make large numbers of existing cars uneconomical to run - it would be far too unpopular.

The Euro VI car that you are looking at will likely have slightly better CO2 and significantly better NOx emissions than the Euro V. As with any car purchase, buy the newest, lowest mileage example that you can afford and if that is a Euro V then so be it. There's no point in spending money you don't have to try and second guess a government policy that can't be predicted.
That’s an extremely eloquent summary of my thoughts. We just don’t know yet, and can’t future gaze. Thank you for your time.

Natjack

Original Poster:

9 posts

95 months

Thursday 1st March 2018
quotequote all
Benrad said:
In the real world the EU6 car will have much lower emissions

EU5 and before might be banned from, or charged to enter, city centres and urban areas. So might EU6, but it's less likely

I doubt either car will be banned outright, I don't think they can increase VED rates but I could be wrong. I suspect they'll rely on increasing cost of fuel to get ICE vehicles off the roads without resorting to banning them.

It's all guess work though, I work in diesel engine development for performance and emissions, but in heavy duty rather than passenger car
Thank you. Would you buy (or recommend to someone you know) a 64 (EU5) plate diesel car with your knowledge in the field? Do you think the value likely to depreciate significantly too?

Benrad

653 posts

170 months

Thursday 1st March 2018
quotequote all
Natjack said:
Thank you. Would you buy (or recommend to someone you know) a 64 (EU5) plate diesel car with your knowledge in the field?
Well put question

I don't have a strong enough feeling about the future to advise against it

Normally I restrict my advice to making sure someone buys something appropriate for them. Lots of town driving, avoid a DPF, consider a plug in hybrid

If you need to drive into a big city regularly then I'd definitely stretch to the EU6. If you really care about the environment then look for something that uses AdBlue (it's a much more robust technology). Beyond that it's impossible to say

Natjack

Original Poster:

9 posts

95 months

Thursday 1st March 2018
quotequote all
Benrad said:
Well put question

I don't have a strong enough feeling about the future to advise against it

Normally I restrict my advice to making sure someone buys something appropriate for them. Lots of town driving, avoid a DPF, consider a plug in hybrid

If you need to drive into a big city regularly then I'd definitely stretch to the EU6. If you really care about the environment then look for something that uses AdBlue (it's a much more robust technology). Beyond that it's impossible to say
Good advice, thank you

Toed64

299 posts

141 months

Friday 2nd March 2018
quotequote all
I share your concerns about pollution legislation, but also the cost of maintenance and repair of modern diesels.

There seems to be an argument that the cost of the higher fuel consumption of petrol cars might be offset by the repair and maintenenance cost of the diesel cars. Consequently, for a 10 year ownership proposition, I think I'd be looking for a petrol version...that has not been smoked in!

Natjack

Original Poster:

9 posts

95 months

Friday 2nd March 2018
quotequote all
Toed64 said:
I share your concerns about pollution legislation, but also the cost of maintenance and repair of modern diesels.

There seems to be an argument that the cost of the higher fuel consumption of petrol cars might be offset by the repair and maintenenance cost of the diesel cars. Consequently, for a 10 year ownership proposition, I think I'd be looking for a petrol version...that has not been smoked in!
Ha ha - we have decided against that one for exactly that reason, but considering an alternative 64 plate! Thank you for your advice.

xjay1337

15,966 posts

139 months

Friday 2nd March 2018
quotequote all
Toed64 said:
I share your concerns about pollution legislation, but also the cost of maintenance and repair of modern diesels.

There seems to be an argument that the cost of the higher fuel consumption of petrol cars might be offset by the repair and maintenenance cost of the diesel cars. Consequently, for a 10 year ownership proposition, I think I'd be looking for a petrol version...that has not been smoked in!
Serious question.
You know many petrol cars have EGR valves.
Diesels are simpler engines and in terms of brute mechanical reliability, often much stronger than the petrol engines equivalents.
I've had a 1.9 TDI Mk5 Golf, Mk5 GTI Golf and a Scirocco TDI, the diesels have been perfectly reliable where as I'd have lots of issues with the GTI , oil pressure , mis fires, fuel pump failure etc... However I know that any car can have problems so in my case I've just been lucky/unlucky smile

Ultimately OP needs to go with a car that suits his needs and budget and not worry too much about stuff like depreciation on a used car most of it's been done already!

Fastdruid

9,275 posts

173 months

Friday 2nd March 2018
quotequote all
xjay1337 said:
Serious question.
You know many petrol cars have EGR valves.
Diesels are simpler engines and in terms of brute mechanical reliability, often much stronger than the petrol engines equivalents.
That's just not true.

Or to put it another way it's misleading with the truth.

Diesels are stronger because they have to be...but everything is more stressed. This means that while modern petrol cars share multiple technologies with diesels the diesel version is far more likely to fail.

Petrol cars have had DMF's for >20 years...but a failure is rare. Petrol cars are smoother which results in less stress and because generally they're not driven round at minimum rpm (when the stress on the DMF is highest) they're highly unlikely to fail.
Petrol cars now have GPF but unlike DPF's they regen on a closed throttle, don't have to be "taken for a long drive" or have some esoteric regen routine and as there is far less soot they should last the life of the vehicle before they're filled with ash.
Petrol cars have had EGR's for 20+ years but again because petrol cars don't produce as much soot they don't clog up like diesels do.
Petrol cars have turbos but again because petrol cars don't produce as much soot they don't clog up like diesels do.
Equally they don't cause runaways if they leak oil.
Petrol cars have direct injection but because the pressures are far lower they are far less likely to fail.
Equally as the the high pressure pumps cannot rely on the lubricity of petrol and don't need as high pressures the tolerances are lower and they are more robust.

Obviously all that stuff *can* fail before I get regaled with tales of "My wife's work colleagues daughters friend once had a petrol car that ate its DMF", with anything there are some makes and models that are more or less reliable and some cars will have issues even while it's not generally the case.

You also with a petrol car you have the ignition system which can cause issues but with modern stuff that's pretty reliable.

Edited by Fastdruid on Friday 2nd March 11:31

xjay1337

15,966 posts

139 months

Friday 2nd March 2018
quotequote all
We can agree to disagree. smile

My experience is based on comparing the TFSI / TSI VW engine against the PD/CR VW engines.

If you want a very reliable car then buy a diesel and remove the DPF and EGR. Problem solved. biggrin

Fastdruid

9,275 posts

173 months

Friday 2nd March 2018
quotequote all
xjay1337 said:
We can agree to disagree. smile

My experience is based on comparing the TFSI / TSI VW engine against the PD/CR VW engines.

If you want a very reliable car then buy a diesel and remove the DPF and EGR. Problem solved. biggrin
At which point it will now fail the MOT.