What is a 'short journey'?

[huw169]

Hi all.
Did a quick search and came up blank, so thought I'd ask.

With all this talk of EGR's and DPF's, and the associated problems with using your van for 'short journeys', I have to be honest that I have no idea what constitutes a 'short journey', or even how many 'short journeys' are tolerable before a 'long journey' is needed to keep the various systems of the van happy. It sounds to me like the soot will only be burn't during a regen, not just any longer journey, so the DPF is always being filled, just at a lower rate maybe when the engine is hotter. Maybe?

This issue concerned me when buying and I would have preferred a petrol, but just none about. I also wanted DSG, which made the petrol search even more challenging, so ended up with an oil burner.

Is a short journey something where the van doesn't get hot, or is it less than 5 miles, less than 10? (Can you see where I'm going with this?)
Is doing Mon to Friday to and from work 5 miles away, then a longer drive at the weekend still considered bad?

I have no idea, but I'm 100% sure there will be much speculation, but is there any published context around this for these Euro 6 engines?
Especially from VW maybe? There must be a technical paper somewhere.

Here's hoping.....

 

[Dellmassive]

More info . . .

DPF Regen, Yellow Light & Adblue - Whats It All About? -

DPF Regen, Yellow light & AdBlue - Whats it all about? - The DFP light is becoming a more apparent issue with modern diesel vans, unfortunately, it’s a fact of modern diesel life. what is a DPF? Diesel particulate filters (DPF) are very effective in cutting emissions, trapping even the...

www.t6forum.com

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[Loz]

In terms of emissions build-up, I would consider a "short journey" as one where the time the exhaust components spend longer below working temperature than above.
This will depend on how you drive and the profile of the drive.
for example, If say it takes 15minutes to get up to optimum temperature, a short journey would be 30 minutes or less.

 

[Kind of Blue]

I agree with Loz, It is important to have the engine up to proper working temperature. To do most driving at working temperature if possible To try to eliminate journeys that do not do so, if preventable. As far as how long one way or another, how long is a piece of string.

 

[DXX]

IMO as far as EGR system is concerned it’s the exhaust temperature that‘s important and that is based on coolant temperature and engine load.
Get the coolant up to ’normal’ running temperature and load the engine where possible if the journeys are short, 5 mile journeys probably isn‘t quite enough in the long term.
Aside from the EGR system the oil temperature takes longer than the engine coolant to reach full operating temperature and even longer for heat to distribute through the whole engine, this drives off moisture through the crankcase ventilation system. A friend of mine was driving her X5 for the 1/2 mile journey to work and was puzzled as to why there were continuous engine problems!

 

[cgtmiles]

For the regen, it has to get up to temp and then stay at high revs for a sustained period (eg. Motorway driving) though doesn’t it. I can’t do this very often so as previously mentioned I try to avoid trips where the engine doesn’t even get up to temp. That’s what the wife’s zafira is for
Even so, I think of this as elongating the engine life not sustaining it, a modern vehicle should be able to cope with stop start journeys surely, there aren’t many long open roads round here and it’s stop start even on the motorways!

 

[t6blo]

At the risk of inflicting impending doom on myself - I currently have a 140 T6, had it nearly 2 years, had a 1.6 Caddy for a year before that, and before that a Golf GTD for 2 years and another GTD for 2 years before that.

Not once in nearly 8 years of VAG diesel ownership have I seen the DPF/EGR light on the dash or had any related problems - my normal commute (prior to Covid) during that time was a 6 mile round trip each weekday (since March the van is hardly being used as I am working from home but that’s another thread entirely!).

The only thing I can say is I do like to drive them hard once they are warmed up.

 

[Kind of Blue]

I agree with posts above. I try only to select drive at the start of an outward journey paricularly if short until warm. I use the paddles to down shift if necessary and then go back up again. Its when warm that I tend to leave it in sport, use the flappies or use manual selection. Mostly my journeys on in the countryside with some parts in smaller towns and villages. DSG is strange, one can only gain direct entry to manual from drive. It would have been more local if manual was gained from sport or from sport and drive. Any way drive allows a higher gear and does not rev out so much unless it is floored so the engine is loaded more and so heats up.

It is reassuring to have t6blo assurances on VAG DPF/EGR systems.

 

[Big Al]

As @t6blo before I got my T6,the other diesel I had was a 2007 A6 TDI and I also had a 5-6 mile commute each day. It did get a run over the weekends but in 3 years I never had any DPF/warning light issues. Que sera I guess.

 

[huw169]

So when I bought my van I did have some reservations as to how i would use it, hence my comment about originally wanting a petrol in post 1.

However, having done a little reading and Carista beta testing, I'm far less worried about the short journey 'perceived issue'.

First worry - DPF
It regens, That's a fact and no way to stop it. Particles collect all the time regardless of how you drive it and need clearing once a tank (ish). It's way better to do the regen as part of a journey rather than letting it tick over as it uses way more fuel at tickover to get the exhaust hot, and there is 0 mpg. If you are mindful of the particulate level and use Carista beta, you can regen it when it suits you.
I agree that VW should have given and on dash indicator, and maybe a method on MFD of triggering it when we know we have a journey, but then maybe that is all the dash light was meant to be - not to flip us into panic mode. But dash warning lights tend to mean trouble, so it's hardly surprising.

Second worry - EGR
The short journey thing and clogging up. Turns out the EGR is closed when the engine is cold, van is stationary, or under acceleration. So short journeys and town driving shouldn't contribute much to the clogging issue. It only really opens fully when you are warm and at steady load, so motorway driving. So looooong journeys are bad!?

Anyway, I'm no expert, as many of you can tell. Just some observations based on my own perceived concerns.
Happy to be corrected by more knowledgeable folk.

 

[Broadside]

Second worry - EGR
The short journey thing and clogging up. Turns out the EGR is closed when the engine is cold, van is stationary, or under acceleration. So short journeys and town driving shouldn't contribute much to the clogging issue. It only really opens fully when you are warm and at steady load, so motorway driving. So looooong journeys are bad!?

Luckily my T6 behaves itself but my previous car had a troublesome EGR issue which only cropped up on long motorway runs, usually after a few hours driving in France. My friends loved it when I went to France because it gave them endless opportunity for p* taking as the engine management light would usually come on!!

 

[widu13]

I did read what VW class as short journeys overall when I signed up for the black friday servicing deal- it was on their van servicing website to differentiate between long life and annual. I was quite surprised by how high the requirements were for long life. >10k pa IIRC correctly for long life and anything else was called short journeys for annual servicing. I skipped over it really, it might mention a specific amount of miles on there?