Diesel Particulate Filter (DPF)

[gaffer1986]

More of a rant than a question

Why does my 1.6 TDI CR have a DPF? My reasoning against is below:

1. A DPF does not reduce the CO2 emissions so the Road Fund Licence (Tax) would be the same without it.

2. I do mainly urban driving so the DPF seems to be regenerating 10% of the time i am driving. Urban driving without the DPF regenerating is about 52 mpg, with the DPF regenerating is about 42 mpg.

3. Whenever it regenerates you get a burning smell, although the burning smell is becoming less aparent the more miles i put on the car (1000 so far). Maybe i am just getting used to the smell?

4. Surely the DPF causes more back pressure and as a result the engine has less power and less mpg than it would without it.

Despite these problems i am happy to say that the DPF light has not come on yet and i have done 1000 miles, however 250 of those miles have been motorway. (had the car 2 weeks now).

Absolutely love the car and am very happy with it, just can't help thinking it would be better without the soot burning DPF. Our environment doesn't have smog problems anymore!

Can anyone cheer me up and tell me an advantage for this smelly, fuel burning, power sapping device under my car?

 

[Molehill_Mike]

2. I do mainly urban driving so the DPF seems to be regenerating 10% of the time i am driving. Urban driving without the DPF regenerating is about 52 mpg, with the DPF regenerating is about 42 mpg.

How do you know when it is, and when its not regenerating?

I have a MK5 ECO, which also has a DPF...assumed it was this that assisted the CO2 emisions being below 100g/km.

Mike

 

[nightflight]

It's there to meet the new emissions regulations for new cars, road fund license is based on c02 emmission, but approval for a new car is based on all emissions, which is where the dpf comes in.

you can tell when it's doing a dpf regen as the engine idles at 1000rpm (annoyingly, 1000rpm i also the resonant frequency of the cabin) as opposed to 750/800rpm when it's not doing one.

it's a pita really, i've tried driving my car more economically, but all that does is get the dpf blocked up quicker forcing me to drive unnecessarily at high revs for about 30 minutes to clear it., so it's back to revving it on anything other than long journeys to get the exhaust up to temp.

CustomCode do/did a DPF-Delete pipe and re-map for the tdi leon's, here's hoping that someone does something similar for the ibiza.

 

[Marcato]

Hi guys, first time post! I have an SC Sport 1.6 Petrol on order, but picked up a bit of information on DPF's while talking with my friend about his Fabia VRS.

The thing with DPF's is that it removes diesel particulates which are known to be carcinogenic, and can therefore lead to lung cancer and numerous other health issues. From what I picked up on Wikipedia numerous governments are now encouraging these now be retrofitted to older vehicles too. Aside from disposing of the harmful waste matter they also help remove between 85% - 100% of the black soot emitted from the exhaust too. I'm sure we've all been stuck behind a smokey Transit van, or older badly maintained diesel at some point and know how unpleasant it can be when a huge plume of black smoke covers your car.

I think the DPF could reduce performance in the same way catalytic converters do, but I'm sure the VAG engineers could, or perhaps already have implemented some kind of feature which dynamically increases the boost pressure to compensate while the DPF is on regen. Afterall, these engines seem good for over 130BHP, so a slight pressure increase should be tolerable. Obviously all this is speculative but in theory it might work.

 

[gaffer1986]

I found this on the VW website.

http://www.volkswagen.com/vwcms/mas...wertrain/start/diesel_particulate_filter.html

To clean the filter, the trapped particulate matter is periodically removed. In passive regeneration, the soot is slowly and gently converted to CO2. This process requires an exhaust temperature of over 630 °C and takes place without the need for special measures, e.g. on the motorway. Only when the vehicle is driven for long periods at low load, e.g. in urban traffic, is the filter actively cleaned.

So the DPF converts soot to CO2, so this actually increases CO2. DPF filters do not reduce CO2 emissions from what i have read.

 

[nightflight]

^ really interesting link that, great find

 

[Frudo]

Dpf update

I was well aware of the dpf and the regeneration required before I purchased my 1.6tdi. Doing mostly urban and town driving I anticipated taking it for the odd regen run. I have not been disappointed !! Just 1290 miles on it now. I kept it under 2000 rpm in all gears for 800 miles, pretty boring, and gradually giving it some beans up to 3000 rpm. Thats the max to date. Did a few 50 mile trips and many short trips up to 914 miles when the dpf light came on for the first time. I had travelled 5 miles when it came on, had to go a further 15 before it cleared. All ok until today at 1264 miles when on the way to the supermarket, had to go on a 21 mile trip at 3000rpm in 3/4 gear before it cleared, was getting a little concerned that it may not clear but it did. The past 2 weeks have been local 5-10 mile trips, I recken I have only done about 150 mile since its last long run and auto regen. On the 4 tank fulls to date I have averaged 45mpg, most of this at less than 2000rpm. Going to change tactics this tank full as recommend by a few on this forum and give its some beans from the onset, not waiting for it to warm up fully, without a temp gauge its difficult, but noticed that it revs at 1000 for quite a while after setting off, bit like having the old choke on for to long. I contacted the dealer and told him of my concerns he said he had heard of a mod that may solve the problem, and would get it touch shortly.Will update when I here.