Leaving tank more than 1/4 full

[Sunstoner]

Yes, I take this approach too although I might replace the tea with beer on occasions!

Now im getting it....all these 'quirks' are purposely designed to further get us outdoors and thus from under the feet of our better halves?! (and wild children - if theyre part of the package) !

 

[2into1]

I try to approach this a bit like a hobby looking after the van

This is good advice... Particularly for owners of older vans where we try and fix problems with old fashioned diagnostics and spanners rather than just swapping out components until it works.

 

[Karlos]

There seems to be more misunderstanding of how a T6 regenerates which is different to all previous models. Rather than regenerate during long, higher revving trips like the older models, the T6 uses a forced regeneration whenever it seems fit, irrespective of your plans at the time. My T6 generally chose about 0.5 miles from home to start. It appears you are unlikely to do more than 2 hours of driving between regens.

VW have realised that the fuel in the system (which constantly recirculates) will overheat during regen if the tank is less than 1/4 full, so have programmed the system to NOT regen below that level.

Even if you've just blasted down the autoroute for 12 hours, there is nothing to say your van wasn't just about to start a regen when you (a) stopped or (b) fell below 1/4 tank.

As there is still plenty of fuel left at 1/4 tank (say 17.5 L), you have 135miles of range at 35mpg, and at Ave 30mph, could drive for over 4 hours. That could be 2 additional regens missed as well as the one that perhaps just likely to be needed. I don't know at what level of failed regens you get a warning light, or the engine cuts out.

This is a vw cock up. Don't assume that because you have no warning lights or alarms, then all is fine. Vw didn't realise this implications of low fuel, so didn't program any warnings. It's taken them a year after we worked it out (with vw guru's help) to start leaving leaflets in your glove box.

May be a stupid question but how do you know regenerate is taking place.

 

[Wolfie]

Interesting indeed.

View attachment 54636

View attachment 54637

Curiouser and curiouser.

Assuming the units are UK gallons, this gives conflicting information as does the leaflet in the OP.
The first photo says that you can put exactly 1.25 gallons in and it will meet both the min and max condition.
However 1.25 UK gallons =5.68 litres. This satisfies the minimum of 4.25 litres but exceeds the maximum of 5.25 litres.

In the OP, the correct conversions are 1.5 gallons = 6.82 litres and 2.25 gallons = 10.23 litres. Putting in 6 litres does not meet the minimum requirement and where did the 9 litres come from? The most obvious quantity would be 10 litres, but would this mean I have over-filled it?

It is not consistent with conversions between US gallons and litres either (just a thought!).

What this highlights is that using a calculator to convert from UK gallons to litres (i.e. multiply by 4.54609) is not a reliable method to determine maximum and/or minimum quantities of AdBlue. Therefore, I am going to stick with using values in litres from the MFD. To avoid any confusion, what is really required is for AdBlue quantities to be permanently in litres, irrespective of the units chosen for fuel consumption. This cannot be beyond the wit of software developers at VW.

 

[2into1]

May be a stupid question but how do you know regenerate is taking place.

I'm a bit out of date having sold my T6, but I remember a slight change in engine note, the stop-start would disable itself. It you stopped the engine mid regen then it would quickly go into hovercraft mode as you walked away (very noisy fans would start up for 5 mins or so).
(edit, as pointed out in a subsequent post, the idle speed increasing to 1000rpm instead on 700 is the clearest signal your T6 is regenerating)

 

[Karlos]

I'm a bit out of date having sold my T6, but I remember a slight change in engine note, the stop-start would disable itself. It you stopped the engine mid regen then it would quickly go into hovercraft mode as you walked away (very noisy fans would start up for 5 mins or so).

Ok thanks, never had the fan sound or noticed an engine note change but have had the start stop disabled.

 

[Toothlessjon]

I wonder if this will affect resale value, if selling private you will have to declare this problem to the buyer. If they are new to VW wouldn’t even en put them off buying? Probably would me tbh.

 

[Christine Kirk]

if you want a real headache , pull over for the night , set up camp and drink an unreasonable amount of beer / wine / whiskey . on the plus side you might stop thinking rationally about the world, and when to refuel, just keep your glass filled.

 

[Christine Kirk]

FYI VW left this in my glove box. Looks like VW are now confirming the tank must be 1/4 full.
View attachment 54391

4.54lts is 1 gallon therefore 10 ltr is 2.2gallons by my calculation or about 18pints.

 

[Karlos]

if you want a real headache , pull over for the night , set up camp and drink an unreasonable amount of beer / wine / whiskey . on the plus side you might stop thinking rationally about the world, and when to refuel, just keep your glass filled.

I'm just going to enjoy mine and ensure it always has more than 1/4 of a tank of fuel and a designated driver so I can have a glass or two.

 

[Christine Kirk]

no cautionary note left in YVone last week when she was in for work at Sheffield VW ; have filled up with UREA (add -blue! ) 3 times now. shows 6000mls interval on the MFD.

 

[Calimili]

I think this is worrying people more than it should.
When you need to refill diesel, refill it to the max.
If MFD says you still have 3500miles of Adblue, keep driving another 1500 miles without panicking and then put 5l or a UK gallon of Adblue in. If you put two bottles of 1,89 each it is also fine. Then keep driving. Don't overstress on this guys..

 

[Karlos]

Put 4 ltrs of Addblue in mine when it was showing 2500miles as we were going to Italy, MFD went to 6000, have done 4000 since and MFD still shows 4000. Not sure if this is down to driving style, but will keep plodding. When the van was delivered the dealer advised let the display get to 750 miles then put 10 litres in.

 

[WelshGas]

I just cannot understand the degree of hair pulling, arm waving and comments regarding " Not fit for purpose" or being put off buying the vehicle.
From my reading around this subject on the T5 DPF regenerations took place automatically as and when conditions were correct and it was required. Those who did short trips constantly ran into problems and if the DPF light came on had to go for a 50mile run, at speed, to force a regeneration or visit the Dealer to force a regeneration.
On the T6 these Regenerations are Forced on a regular basis by the EMU, BUT in order to do this the Fuel levels have to be above a certain level and VW issued this recommendation to ensure that fuel levels are sufficient and to avoid problems caused by the driver who waits until the fuel light comes on and puts in £5 of diesel. They will run into problems IF DONE CONSISTENTLY.
If you drive until the Fuel Light comes on and put in a minimum of 20L of diesel then you won't have the problem. The vehicle will be able to do its Regular/Timed Regenerations.

This is the Result of the EU Pollution regulations and the fact that some numpties don't understand how the system works and run around with the Fuel Light ON and piping in £5 of fuel at a time.

Are you one of these? Probably not and so you will have No Problems.

Even on the T6 Forum, mainly commercial vehicles, it has Not generated as many comments as on here.

In summary, Use it or Lose it. Only if you do a lot of small trips should you ensure Fuel levels are above 1/4 tank. Likewise if you use the Diesel Heater then the same fuel levels are required or the Heater won't fire up.

 

[WelshGas]

Put 4 ltrs of Addblue in mine when it was showing 2500miles as we were going to Italy, MFD went to 6000, have done 4000 since and MFD still shows 4000. Not sure if this is down to driving style, but will keep plodding. When the van was delivered the dealer advised let the display get to 750 miles then put 10 litres in.

You use less Adblue during Motorway miles and more in Commuter trips.

 

[Lightning]

I just cannot understand the degree of hair pulling, arm waving and comments regarding " Not fit for purpose" or being put off buying the vehicle.
From my reading around this subject on the T5 DPF regenerations took place automatically as and when conditions were correct and it was required. Those who did short trips constantly ran into problems and if the DPF light came on had to go for a 50mile run, at speed, to force a regeneration or visit the Dealer to force a regeneration.
On the T6 these Regenerations are Forced on a regular basis by the EMU, BUT in order to do this the Fuel levels have to be above a certain level and VW issued this recommendation to ensure that fuel levels are sufficient and to avoid problems caused by the driver who waits until the fuel light comes on and puts in £5 of diesel. They will run into problems IF DONE CONSISTENTLY.
If you drive until the Fuel Light comes on and put in a minimum of 20L of diesel then you won't have the problem. The vehicle will be able to do its Regular/Timed Regenerations.

This is the Result of the EU Pollution regulations and the fact that some numpties don't understand how the system works and run around with the Fuel Light ON and piping in £5 of fuel at a time.

Are you one of these? Probably not and so you will have No Problems.

Even on the T6 Forum, mainly commercial vehicles, it has Not generated as many comments as on here.

In summary, Use it or Lose it. Only if you do a lot of small trips should you ensure Fuel levels are above 1/4 tank. Likewise if you use the Diesel Heater then the same fuel levels are required or the Heater won't fire up.

How do you know this?
How many regenerations can you miss before it’s a problem?
What inside knowledge do you have to confidently contradict the manufacturers operating instructions? You know better than them?
Why is it ok to leave the tank less than 1/4 full if you only do long runs?

 

[WelshGas]

How do you know this?
How many regenerations can you miss before it’s a problem?
What inside knowledge do you have to confidently contradict the manufacturers operating instructions? You know better than them?
Why is it ok to leave the tank less than 1/4 full if you only do long runs?

I suggest you read what I said. Nowhere did I say anything about leaving the tank with less tan 1/4 tank on long runs. If on a long run and fuel levels drop below a 1/4 then fill up a minimum 20L and regeneration will take place, if required.
Yes, I do know better than them. They are trying to get to the numpties who REGULARLY run with fuel levels of 20L or less and wonder why they get problems with DPF Regeneration. Are you one of them? No, because you have a TSI and don't you love to go on about it.

 

[Lightning]

I suggest you read what I said. Nowhere did I say anything about leaving the tank with less tan 1/4 tank on long runs. If on a long run and fuel levels drop below a 1/4 then fill up a minimum 20L and regeneration will take place, if required.
Yes, I do know better than them. They are trying to get to the numpties who REGULARLY run with fuel levels of 20L or less and wonder why they get problems with DPF Regeneration. Are you one of them? No, because you have a TSI and don't you love to go on about it.

Hmmm, this is what you actually wrote:
‘Only if you do a lot of small trips should you ensure Fuel levels are above 1/4 tank.’

Again, how do you know what their intent is? You assume you know, but you don’t actually know. So, once again your opinion is not actually fact based.

I don’t love going on about it. I do think it’s important for people to base their decisions on how they use their vans on advice from the manufacturer.

 

[Calimili]

Hmmm, this is what you actually wrote:
‘Only if you do a lot of small trips should you ensure Fuel levels are above 1/4 tank.’

It would be difficult to do a long run with fuel below 1/4 Tank. There isn't enough fuel. I think you are misunderstanding the point WG is making, which is consistent with VW instructions

 

[WelshGas]

Hmmm, this is what you actually wrote:
‘Only if you do a lot of small trips should you ensure Fuel levels are above 1/4 tank.’

Again, how do you know what their intent is? You assume you know, but you don’t actually know. So, once again your opinion is not actually fact based.

I don’t love going on about it. I do think it’s important for people to base their decisions on how they use their vans on advice from the manufacturer.

I had already stated that on a long trip just fill up when the Fuel Light comes on.
A friend runs 4 Euro 6 Caravelle taxis. They do airport runs. They start with full tanks and run until the fuel light comes on then the drivers put in 20L and continue until they get home or the fuel light comes on again when the process is repeated until they get back to base and are filled up. All have milages in excess of 100K and no problems with EGR , DPF or Adblue system.
Real world evidence that letting fuel levels drop below 1/4 tank cause no problems only running consistently below that level can be problematic.

 

[Lightning]

It would be difficult to do a long run with fuel below 1/4 Tank. There isn't enough fuel. I think you are misunderstanding the point WG is making, which is consistent with VW instructions

This is what he said:
‘Only if you do a lot of small trips should you ensure Fuel levels are above 1/4 tank.’
He subsequently said this:
‘Nowhere did I say anything about leaving the tank with less tan 1/4 tank on long runs.’
He then said this:
‘Yes, I do know better than them. They are trying to get to the numpties who REGULARLY run with fuel levels of 20L or less and wonder why they get problems with DPF Regeneration.‘

There is no misunderstanding on my part, as the point he is making is not consistent with VW instructions.

 

[Toothlessjon]

if you want a real headache , pull over for the night , set up camp and drink an unreasonable amount of beer / wine / whiskey . on the plus side you might stop thinking rationally about the world, and when to refuel, just keep your glass filled.

I will instantly take your advice, cheers.

 

[Lightning]

I had already stated that on a long trip just fill up when the Fuel Light comes on.
A friend runs 4 Euro 6 Caravelle taxis. They do airport runs. They start with full tanks and run until the fuel light comes on then the drivers put in 20L and continue until they get home or the fuel light comes on again when the process is repeated until they get back to base and are filled up. All have milages in excess of 100K and no problems with EGR , DPF or Adblue system.
Real world evidence that letting fuel levels drop below 1/4 tank cause no problems only running consistently below that level can be problematic.

Ok, so your in depth survey of your mates taxis, and inherent wisdom, is sufficient to outweigh the entire knowledge base and expertise of the global vehicle manufacturer.
While I hold out little hope for you, maybe others can be saved!

 

[WelshGas]

Ok, so your in depth survey of your mates taxis, and inherent wisdom, is sufficient to outweigh the entire knowledge base and expertise of the global vehicle manufacturer.
While I hold out little hope for you, maybe others can be saved!

In VWs statement they say that having a fuel level less than 1/4 full MAY prevent DPF regeneration. In practice running below that level and then refilling to above that level, at the first opportunity, has no effect on the DPF regeneration.

Oh, and the fabled expertise of a global manufacturer that was responsible for Diesegate.

 

[Lightning]

In VWs statement they say that having a fuel level less than 1/4 full MAY prevent DPF regeneration. In practice running below that level and then refilling to above that level, at the first opportunity, has no effect on the DPF regeneration.

Oh, and the fabled expertise of a global manufacturer that was responsible for Diesegate.

So, the manufacturer has issue instructions to the keep the tank more than 1/4 full as it will prevent regeneration which may cause DPF problems.

You however do not consider it necessary to follow these instructions as in your view refilling ‘at the first opportunity‘ has no effect on regeneration.

You have no evidence upon which to base this conclusion. Your conclusion contradicts the instructions issued by VW.

‘At the first opportunity’ means nothing.

‘Has no effect in regeneration’ is again your opinion based upon no facts. If the tank is less than 1/4 full regeneration does not occur. How many times can this happen before a problem develops? You don’t know?

If people don’t follow the manufacturers instructions and subsequently encounter a problem, then it may well be them and not VW, and certainly not you, who have to foot bill.

To ignore manufacturers instructions yourself is one thing, to advise others to follow suit without possessing the technical knowledge to be able do so, is another.