what annual km's do you need to do to own a modern diesel

patrickc

theres always people looking for advice on cars here, and many do low km's per year and a petrol is recommended.

so what annual km's do ye think one need to be doing to justify a modern diesel.

also are the dmf/dpf filters less likely to bugger up if your doing bigger mileage?

CiniO

patrickc wrote: »

also are the dmf/dpf filters less likely to bugger up if your doing bigger mileage?

It's not about how many miles do you drive, but rather if you do city driving,, or motorway/openroad driving.
City is way worse for both of above

gpjordanf1

CiniO wrote: »

It's not about how many miles do you drive, but rather if you do city driving,, or motorway/openroad driving.
City is way worse for both of above

Shouldn't any car once its reached optimal engine temperature operate properly, regardless of where its been driven and at what speed?

Otherwise in my opinion its not fit for purpose??

barura

gpjordanf1 wrote: »

Shouldn't any car once its reached optimal engine temperature operate properly, regardless of where its been driven and at what speed?

Otherwise in my opinion its not fit for purpose??

Nipping down to the shops doesn't heat up diesels enough to get their DPF working. You need to give em a good 20 minutes drive to get them going.

Yakuza

gpjordanf1 wrote: »

Shouldn't any car once its reached optimal engine temperature operate properly, regardless of where its been driven and at what speed?

Otherwise in my opinion its not fit for purpose??

Nonsense. A car that has reached its optimal temperature by chugging along in stop-start traffic will be far less fuel effecient than one that has reached it by doing motorway speeds, whether it be petrol or diesel. With a modern diesel, driving in stop start traffic just builds up gunk in the DPF, while going at motorway speeds will burn it off.

The original question can't be answered in terms of mileage alone. You need to factor in tax, depreciation, insurance and servicing costs as well as fuel bills. How long you plan to keep it is a factor as well.

If all the other factors were the same(ish), then here's a crude example. Say there's a 3k extra cost in buying the diesel, and you plan to keep it for 10 years, then you need to be saving €300 a year to justify it. If you do mostly motorway driving, say you get 2 l/100 km better out of a diesel. €300 is roughly 200 litres. Saving 200 litres @ 2l/100km means you should be doing at least 10000k per year.

JaneyMacker

DPFs are a disaster.
So glad my car doesnt have one.

Nissan doctor

Constant city driving or short trips isn't good for a petrol car either, if just tends not to have the expensive consequences that modern diesels can have.

As for a modern diesel not being fit for purpose, that rubbish. DPF's need to be used and regenerated as per the guidelines in a cars owners manual. If a DPF fails due to constant city driving/short trips, that failure is due to misuse by its owner. If they chose not to read the manual or research how to use their €20k+ investment thats not the vehicle manufacturers fault.

gpjordanf1

barura wrote: »

Nipping down to the shops doesn't heat up diesels enough to get their DPF working. You need to give em a good 20 minutes drive to get them going.

20 mins wow thats slow, min heats up in about 5 minutes.

Yakuza wrote: »

Nonsense. A car that has reached its optimal temperature by chugging along in stop-start traffic will be far less fuel effecient than one that has reached it by doing motorway speeds, whether it be petrol or diesel. With a modern diesel, driving in stop start traffic just builds up gunk in the DPF, while going at motorway speeds will burn it off.

The original question can't be answered in terms of mileage alone. You need to factor in tax, depreciation, insurance and servicing costs as well as fuel bills. How long you plan to keep it is a factor as well.

If all the other factors were the same(ish), then here's a crude example. Say there's a 3k extra cost in buying the diesel, and you plan to keep it for 10 years, then you need to be saving €300 a year to justify it. If you do mostly motorway driving, say you get 2 l/100 km better out of a diesel. €300 is roughly 200 litres. Saving 200 litres @ 2l/100km means you should be doing at least 10000k per year.

Did you actually read the question?? Nobody is on about fuel efficency? But just to add my 2cs on your point, I switched from a petrol to a diesel and am saving €150 a month

Nissan doctor wrote: »

Constant city driving or short trips isn't good for a petrol car either, if just tends not to have the expensive consequences that modern diesels can have.

As for a modern diesel not being fit for purpose, that rubbish. DPF's need to be used and regenerated as per the guidelines in a cars owners manual. If a DPF fails due to constant city driving/short trips, that failure is due to misuse by its owner. If they chose not to read the manual or research how to use their €20k+ investment thats not the vehicle manufacturers fault.

Ah sorry I didn't realise small diesel city commuter's were actually designed to be Motorway milers. Silly how did I get that wrong??
So if you actually take it to the motorway once every 3,500 to 5,000 kms (as per my manual ) then you should be ok??

johnos1984

gpjordanf1 wrote: »

20 mins wow thats slow, min heats up in about 5 minutes.

I imagine the engine temp reaches it's correct level in 5 mins, not the dpf

And NO, modern diesels aren't suitable for stop/start city driving

Nissan doctor

gpjordanf1 wrote: »

20 mins wow thats slow, min heats up in about 5 minutes.



Did you actually read the question?? Nobody is on about fuel efficency? But just to add my 2cs on your point, I switched from a petrol to a diesel and am saving €150 a month



Ah sorry I didn't realise small diesel city commuter's were actually designed to be Motorway milers. Silly how did I get that wrong??
So if you actually take it to the motorway once every 3,500 to 5,000 (as per my manual ) then you should be ok??

Diesel cars have always been aimed at higher mileage and/or motorway mileage. The reason small diesels are now being put into smaller(previously city) type cars is for no other reason then companies have to lower their C02 emissions in line with euro regulations and because, in most markets, tax/vat is lower for lower emissions vehicles.

Diesels have always created smoke and diesel particulates and they have always clogged up when driven short distances. But on old tech diesels all that was needed was a bit of fuel additive and a good drive to clear them out. With modern engines, which have much finer tolerances as well as DPF's are prone to expensive problems if they are allowed to clog up. You even need to use very specific oil types for vehicles fitted with DPF's.

Also, with regards to engines getting up to temperature, diesels take longer to get up to operating temperature the petrol engines.

The simple fact is, most people don't know any if this and have just jumped on the diesel/low tax bandwagon thinking they can drive them like they have always driven their previous petrol cars.

Yakuza

gpjordanf1 wrote: »

Did you actually read the question?? Nobody is on about fuel efficency?

Did you actually read my reply??
The first paragraph was directed at the nonsensical statement you made about a car not being fit for purpose as didnt operate optimally at the right temperatrure irregardless of how it's being driven.

*Then* I asserted that in my opinon, mileage alone shouldn't be the sole criteria in justifying a diesel, but you should take other running costs into account.

*Finally* I did answer the OPs question (making an assumption to ignore differences in other running costs between petrol and diesel) by using some back of the envelope figures of the price difference, the economy on motorway runs and the current price of fuel.

gpjordanf1 wrote: »

But just to add my 2cs on your point, I switched from a petrol to a diesel and am saving €150 a month

Glad to hear it. Is that mostly city or motorway driving?

Eric Cartman

realistically anyone doing under 20k kms a year and/or doing 60% or more city driving petrol is your best option

patrickc

i'm not thinking of buying a modern diesel btw, just said I'd ask here as so many talk about the usage of modern diesels etc in other threads.

gpjordanf1

Yakuza wrote: »

Did you actually read my reply??

Why yes I did!

Yakuza wrote: »

The first paragraph was directed at the nonsensical statement you made about a car not being fit for purpose as didnt operate optimally at the right temperatrure irregardless of how it's being driven.

That isn't what I said at all, wow talk about getting it completely wrong! My point was the once a car reaches optimal temperature then it should be running at peak engineering efficency for the conditions it finds itself in. Be that town or motorway.

Yakuza wrote: »

*Then* I asserted that in my opinon, mileage alone shouldn't be the sole criteria in justifying a diesel, but you should take other running costs into account.

Wow again amazing lack of understanding. Mileage in any car directly relates to all its other running costs, this provides a broad blanket of all running costs. The more mileage you do you the more running costs associated with it!

Yakuza wrote: »

*Finally* I did answer the OPs question (making an assumption to ignore differences in other running costs between petrol and diesel) by using some back of the envelope figures of the price difference, the economy on motorway runs and the current price of fuel.

I think you figures aree actually wildly inaccurate based on my own real world comparasion.

Yakuza wrote: »

Glad to hear it. Is that mostly city or motorway driving?

Neither actually, town, national & country roads. 60+MPG

vectra

I just wonder if all the posted here giving advice on DPF's and short journeys actually own a diesel car with a dpf and have actually had this issue because of the driving style?

bazz26

vectra wrote: »

I just wonder if all the posted here giving advice on DPF's and short journeys actually own a diesel car with a dpf and have actually had this issue because of the driving style?

I had to replace the DPF on my previous Volvo S40 last year at 80k miles. Cost me almost €1000 and it was totally blocked up. I drive about 22k miles a year mostly outside the city but it looks like the damage was done by the previous owner.

Nissan doctor

vectra wrote: »

I just wonder if all the posted here giving advice on DPF's and short journeys actually own a diesel car with a dpf and have actually had this issue because of the driving style?

I own a common rail diesel without a DPF but I do regularly have to diagnose/repair diesel engines with use related faults.

The main things that effect the reliability/longevity of modern diesels, in my experience, are:

• Poor servicing, mainly incorrect oil type,
• Incorrect use, non regen of DPF, constant city driving reducing the life of the DMF
• Poor quality/washed diesel, effecting pumps/injectors etc

dharn

i drive a bmw 320d usually buy one 3 years old do small mileage but love the torque and acceleration i sometimes wonder would i be better off with a 320i but im not sure depreciation had leveled the price more or less service cost are much the same diesel is much more economical petrol is now dearer than diesel in some places so for me diesel versus petrol with small mileage makes little difference or am i missing something

Nissan doctor

dharn wrote: »

i drive a bmw 320d usually buy one 3 years old do small mileage but love the torque and acceleration i sometimes wonder would i be better off with a 320i but im not sure depreciation had leveled the price more or less service cost are much the same diesel is much more economical petrol is now dearer than diesel in some places so for me diesel versus petrol with small mileage makes little difference or am i missing something

Especially with the market the way it is now, if I was only doing very low miles I'd have a petrol model in a heart beat.

In your case, the 320D's have good power and torque, but also lots of potentially expensive repair bills but then so does the petrol 2.0, 4 cylinder N series engines so I'd be trying to find a mint older 6 cylinder model.

vectra

20k kms on my diesel and a lot of it has been stop start to the shops etc. No dpf lights yet.. I do let it "clear it's throat" so to speak once in a while though on the open road

Nissan doctor

vectra wrote: »

20k kms on my diesel and a lot of it has been stop start to the shops etc. No dpf lights yet.. I do let it "clear it's throat" so to speak once in a while though on the open road

I wouldn't be expecting any problems at 20k regardless of use anyway:)

s14driftking

does a 530d 00 have this dpf as well as the crabk case breather or are they both the same thing

Nissan doctor

s14driftking wrote: »

does a 530d 00 have this dpf as well as the crabk case breather or are they both the same thing

They are two completely different things and a 00 530 doesn't have a DPF.

s14driftking

Nissan doctor wrote: »

They are two completely different things and a 00 530 doesn't have a DPF.

thank u one less thing to worry about lol

vectra

Nissan doctor wrote: »

I wouldn't be expecting any problems at 20k regardless of use anyway:)

Buddy of mine, His father bought a Polo tdi the same time as I bought the Cordoba tdi. His Polo went back 3 times in 12 months with dpf probs. Now he pottered about town. I would safely say the car never saw more then 1,500~2,000 rev's though.. eventually he had to do a deal with the dealer and exchanged it for a petrol one.

EPM

dharn wrote: »

i drive a bmw 320d usually buy one 3 years old do small mileage but love the torque and acceleration i sometimes wonder would i be better off with a 320i but im not sure depreciation had leveled the price more or less service cost are much the same diesel is much more economical petrol is now dearer than diesel in some places so for me diesel versus petrol with small mileage makes little difference or am i missing something

Use punctuation in future. If you dont your posts will be deleted.

_Kaiser_

Aside from the flywheel needing replacing and (almost) quarterly servicing that's never been the price quoted at the start , mine hasn't given any issues really.

But then it's doing 1000km a week - 95% of which is at motorway speeds - so it gets plenty of opportunity to clear it's throat (and my wallet ) - 201xxx km and rising...

vectra

Kaiser2000 wrote: »

Aside from the flywheel needing replacing and (almost) quarterly servicing that's never been the price quoted at the start , mine hasn't given any issues really.

But then it's doing 1000km a week - 95% of which is at motorway speeds - so it gets plenty of opportunity to clear it's throat (and my wallet ) - 201xxx km and rising...

What car? :eek:

dharn

EPM wrote: »

Use punctuation in future. If you dont your posts will be deleted.

sorry, i did not know this was a grammar class, will try to improve in the future:)

dharn

Nissan doctor wrote: »

Especially with the market the way it is now, if I was only doing very low miles I'd have a petrol model in a heart beat.

In your case, the 320D's have good power and torque, but also lots of potentially expensive repair bills but then so does the petrol 2.0, 4 cylinder N series engines so I'd be trying to find a mint older 6 cylinder model.

thanks doc but when were the last 6 cylinders made

polod

What about the EGR valves, do they not block up with short trips too? I once had a problem with one in my old car, and my mechanic told me to use the fuel additives to clean it out, to stop it from sticking I got rid of that car after as it was giving other problems, but surly a fuel additive wouldn't clean out an EGR valve would they ?

_Kaiser_

vectra wrote: »

What car? :eek:

06 2L TDI Passat with DSG - I bought it in April 08 with 56000 on the clock and today she has 201547 km

But that said, she also has a full main dealer history and gets serviced (more-or-less) on time.. with the mileage I do, shelling out maybe €1200 a year upwards on servicing does bite, but then again, no car.. no job!
Getting a bus isn't an option and there ARE no trains/DARTs out this way. Moving isn't a runner either what with short-term unpredictable contracts (but that's another thread )

Besides, I hate having even so much as a bulb out, never mind warning lights on the dash, odd rumbles etc..

Nissan doctor

polod wrote: »

What about the EGR valves, do they not block up with short trips too? I once had a problem with one in my old car, and my mechanic told me to use the fuel additives to clean it out, to stop it from sticking I got rid of that car after as it was giving other problems, but surly a fuel additive wouldn't clean out an EGR valve would they ?

Yes EGR's are also effected by low RPM driving too although with EGR's, they can fail on petrols as much as diesels with that kind of driving.