Paul wrote: ↑Sun Jul 22, 2018 10:25 pm
...also, re the original dpf filter point, driving at 2000 rpm won’t clean the filter unless the regeneration process has been initiated by the car.
It won’t do any harm and the higher temps may help keep the soot down but only the car can decide when it wants to regenerate the particulate filter.
So would I know when the regeneration process is going to happen or does it just do it when it fancies it?
Passive regeneration happens without you knowing - a bit more fuel is put through the system to make the exhaust run a bit hotter - you might notice a drop in revs momentarily but probably not.
Active regeneration is when the light comes on on the dash and that is when you should, if you can, drive for 15 mins at 2000 rpm with at least 1/4 tank of fuel etc etc.
Is there really any difference between 'active' and 'passive' - I thought (BICBW) that it was all the same regeneration process. And then any difference might be:
No warning: When the electronics and soot sensor decide that a regen is needed and the driving conditions are such that it can go ahead right away.
MFD warning: Regen is needed but driving conditions are not compatible with a background regen and so the driver must adapt driving conditions (eg engine rpm, fill up if necessary etc) so as to be compatible with a regen starting automatically.
johnd wrote: ↑Mon Jul 23, 2018 9:58 am
Is there really any difference between 'active' and 'passive'
A fair question but I think yes.
As Paul said, Passive regeneration is when the car does it without you knowing, it's a normal diesel process and many cars do this throughout their lives without the owners knowing. In other words, the driving conditions suit the car.
Active regen is when passive regens haven't been able to keep on top of the soot buildup, probably because the driving conditions haven't been suitable. The difference here is that higher temperatures are needed for longer within the DPF to burn off the soot overload. If this is done effectively and promptly, and driving conditions permit, there's a good chance that passive regens can then maintain the DPF soot burden as normal.
Paul wrote: ↑Sun Jul 22, 2018 10:25 pm
...also, re the original dpf filter point, driving at 2000 rpm won’t clean the filter unless the regeneration process has been initiated by the car.
It won’t do any harm and the higher temps may help keep the soot down but only the car can decide when it wants to regenerate the particulate filter.
So would I know when the regeneration process is going to happen or does it just do it when it fancies it?
In my experience, it happens whenever some idiot pulls out of a side road in front of me and floors it, filling my view with clouds of black smoke
Used to have 2016 Macan Turbo PHCKCL70
Previously a 2014 Macan Turbo.
Now a 2021 Tesla Model 3 LR
Wilpert wrote: ↑Sun Jul 22, 2018 11:06 pm
So would I know when the regeneration process is going to happen or does it just do it when it fancies it?
In my experience, it happens whenever some idiot pulls out of a side road in front of me and floors it, filling my view with clouds of black smoke
That's the DPF-removed option.
Our stable:
- 992 Carrera T - manual - Ruby Star Neo - Carrera Excl. wheels (2023)
- BMW 240i xDrive (G42) - Portimao Blue - AC Schnitzer tune ex: 981 Cayman GTS, Macan S Diesl, Macan Turbo, 991.2 Carrera S, 718 Cayman GTS, i30 N, 718 Cayman GTS 4.0
Paul wrote: ↑Mon Jul 23, 2018 9:44 amPassive regeneration happens without you knowing - a bit more fuel is put through the system to make the exhaust run a bit hotter - you might notice a drop in revs momentarily but probably not.articulate-filters/
That sounds like active regen, passive is just it burning off due to temperature of exhaust during normal driving without extra fuel and making engine work harder should increase exhaust temp and increase passive burn
johnd wrote: ↑Mon Jul 23, 2018 9:58 am
Is there really any difference between 'active' and 'passive' - I thought (BICBW) that it was all the same regeneration process. And then any difference might be:
No warning: When the electronics and soot sensor decide that a regen is needed and the driving conditions are such that it can go ahead right away.
MFD warning: Regen is needed but driving conditions are not compatible with a background regen and so the driver must adapt driving conditions (eg engine rpm, fill up if necessary etc) so as to be compatible with a regen starting automatically.
Passive the computer is doing nothing specific and soot is burning off (or not) just due to normal exhaust running temps, active is when it has decided it needs to help burn, light is when it is getting into serious trouble and the driver must do something to help.
Presumably then if you drive in a way that keeps the temp and gas flow up you'll never have a worry?
I wondered why they don't routinely lag the manifold and pipe to the DPF, might just add a few degrees to the exhaust gas.
I've been buying a bit of AdBlu lately and can't see that the amount used by cars makes the system worth installing; the impact on pollution from the exhaust must be minimal if you can do 10k miles on a refill. Bulk it's coming in sub 60p per litre so don't get ripped off!
Tim
PP Turbo, LED PTV ACC Pano 20"Macans collected 6th September 2017
1992 928GTS
2003 996 Cab
Tim92gts wrote: ↑Wed Jul 25, 2018 9:52 am
Presumably then if you drive in a way that keeps the temp and gas flow up you'll never have a worry?
I wondered why they don't routinely lag the manifold and pipe to the DPF, might just add a few degrees to the exhaust gas.
I've been buying a bit of AdBlu lately and can't see that the amount used by cars makes the system worth installing; the impact on pollution from the exhaust must be minimal if you can do 10k miles on a refill. Bulk it's coming in sub 60p per litre so don't get ripped off!
Yes if your driving style and typical drive keeps temp up you shouldn't have to worry
I wonder if one of the problems is they have changed engine mapping with software updates due to cheat software, if they have reduced temp (and efficiency) for certain conditions typical of traffic to reduce NOx it is impacting DPF some driving styles/journeys
Tim92gts wrote: ↑Wed Jul 25, 2018 9:52 am
Presumably then if you drive in a way that keeps the temp and gas flow up you'll never have a worry?
I wondered why they don't routinely lag the manifold and pipe to the DPF, might just add a few degrees to the exhaust gas.
I've been buying a bit of AdBlu lately and can't see that the amount used by cars makes the system worth installing; the impact on pollution from the exhaust must be minimal if you can do 10k miles on a refill. Bulk it's coming in sub 60p per litre so don't get ripped off!
Yes if your driving style and typical drive keeps temp up you shouldn't have to worry
I wonder if one of the problems is they have changed engine mapping with software updates due to cheat software, if they have reduced temp (and efficiency) for certain conditions typical of traffic to reduce NOx it is impacting DPF some driving styles/journeys
The DME software “upgrade” in Spring 2017 definitely changed the dpf soot collection as prior to that never had any regen warnings in the 2 previous years. After that was getting the grey coloured warnings every 2 to 3 months necessitating a 15 mins spirited motorway run at 2000 + rpm . I am fortunate as I live within 5 mins of a motorway junction. I always clear the dpf straight after the warning and run the car in sport mode and manual 6th gear.
With my new Macan I have had 2 warnings since collecting in March and have done 2500 miles but due to change in family circumstances I have not done as many M way miles as I would like.
