Thank you for clarifying dpf/fap. I'm not really interested in the technicalities of how these systems work, just need to find others with similar problems.
There is a problem with this DV6 engine as fitted to the newer Xsara Picassos.(110bhp).
What i'm trying to prove is whether it's the fuelling of the engine or the fitting of this fap system. To find others who have experienced a significant increase in fuel consumption between dpf/fap fitted cars as compared to non dpf/fap cars,of same make/model irrespective of marque, is my main concern.
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You are missing the point, DPF and FAP work totally differently. A FAP equipped car injects the Eolys liquid into the fuel tank every time the car is refuelled (actually every time the fuel flap is opened). A FAP car should not be using any extra fuel.
A DPF car may use extra fuel to help clear the DPF filter.
So the way these work does matter.
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Well can you tell me why identical cars (except FAP) vary so much (10%) in fuel consumption? Journeys same every week/month--tests carried out over 6500miles, to cover all variables. Driver has 3+yrs previous experience. Both cars checked out on Citroen system (for gearing etc) and only difference is FAP.
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only difference is FAP.
no its not
How many miles had your previous car done, and how many miles has this car done.
Wha was the fuel consumption on your previous car and what is it on your current car.
Also - how are you measuring it? and when?
Edited by Altea Ego on 01/09/2009 at 16:33
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What makes you say that the 2 versions of the car that you are comaparing are the same with the exception of the FAP?
Previously (around 2005-6) the FAP was only fitted on the 110bhp version of this engine - the 90bhp was FAP free. Im not sure that this is true of the latest production run.
Can you quote the details of the previous car - yr, model, mileage and the consumption that you obtained? Not spurious single figures or on board displayed computer reading, proper longterm brim to brim measurements. ( I have an interest, as I have a 2006 30k 1.6 HDi 90bhp, with comprehensive consumption figures).
Edited by pmh3 on 01/09/2009 at 17:25
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1st Pic was new in 2005, replaced in Nov.2008@ 28000mls. HDI 110diesel -NON FAP
Filled to brim every time and calculated out, not on board computer which is useless. Over 31/2yrs fuel consumption was between 50and 55 mpg depending on journey and speed. Most common return was 51.4mpg.
2ndPic. New Nov 2008, hdi 110diesel FAP. Fuel tests same as first car and from mainly same sources. Journeys very similar as is speed. Over 6500mls, fuel varies from 43mpg to 55mpg, most common is 47.? mpg. Between Nov 2008 and now, only twice over 50mpg and under very suspicious circumstances.(asda diesel--as was 43mpg). Looking for someone with same experience who can quote their own properly calculated fuel figures in relation to FAP and NON FAP cars.
HDI 90 has no FAP. but poor fuel figures may be caused by stack tollerance---Ask your CITROEN DEALER to explain that one!!!!!!!!!!!
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Does the car do lots of short journeys or urban journeys when your speed doesn't go above 40mph.
If so, the particle filter (FAP) will be constantly trying to re-generate & be wasting fuel trying to heat the filter.
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If they have a FAP filter and not DPF then regeneration uses the eolys fluid in the diesel to catalyse the particles. I didn't think a FAP suffered in the same way as a DPF with regeneration but the eolys fluid is expensive.
Sine the OP says the car is an 08 then it is likely to have a DPF and therefore will be affected as dieselnut says. And it will be a DPF and not a FAP.
Edited by rtj70 on 06/09/2009 at 16:12
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Eolys just wraps each carbon particle in the catalyst to allow it to burn at a lower temperature.
Extra fuel is still required to raise the exhaust temperature if the engine is lightly loaded as in lots of town use.
Don't know if Citroen still uses the Eolys system but I suspect they do, it must be a good money making service item for them.
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It does'nt really matter about length of journey--I'm comparing one car against another.Nothing about lifestyle, driving or anything else has changed. One day i had one car, the next day i had another car--so why a 10% increase in mpg? FAP is the only differing factor. Has no one out there replaced their car with the same model and had widely differing fuel returns?????
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It does matter about the length of journey when you have a FAP equiped car.
If you do short journeys the system will be constantly trying to regenerate the FAP filter which wastes fuel & results in poor fuel consumption figures.
On long journeys the FAP will have niglible affect on consumption.
Just trying to help you understand how this system works.
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Dieselnut, thanks for clarification, very helpful indeed. Are you in a position to quote figures for increased fuel consumption? or %age. Can you tell us how you know all this about FAP?
Promises Delivered--My foot!!!!!!
Edited by seek as a pig on 08/09/2009 at 22:10
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Dieselnut, forgot to ask if FAP system can be taken off car--Citroen reckon it can't but I fail to see why not. Probably need some adjustments to ECU, or remap.
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I know quite a bit about this system after regretfully buying a C5 2.2Hdi that had the FAP system.
I had previously owned Citroen diesels for the previous 20 years & had been very pleased by their outstanding fuel efficiency.
My previous car was an XM with 2.5 old technology IDI engine & the new C5 was 20% less fuel efficient.
I didn't know this FAP system even existed before I bought the C5 secondhand.
Obviously I wouldn't have bought this if I had as I do a lot of short journeys.
Within 2 weeks of buying the car I was getting the fault codes read for the 'Blocked diesel filter' alarm on the display.
I cleaned out the filter myself & topped up the Eolys as dealers were quoting £700, this improved fuel consumption about 5 to 10%, but it was still poor. I never managed to get over 50MPG even driving like a Nun.
I too thought about getting the system removed but realised it would need an ECU re-map & a pipe to replace the FAP filter, so cut my losses & bought a Passat with 1.9PD engine. Now getting 55 - 60 MPG on runs & even 45 - 50 on my 2 mile journey to work.
Not all particulate systems are the same though, my son has a 2.0l common rail Passat with particulate filter & is getting over 60 mpg on his mixed 40 mile town/ A road/ motorway journey to work.
I'll be avoiding any vehicle with this system for the time being.
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Thanks very much indeed Dieselnut, this is the sort of reply i have been waiting for. Unfortunately, your experience was with a C5 and not a Picasso, so not a direct comparison. Nevertheless, it shows people just how this adaption affects their car, and it's economy.
Now for the big rub! You state that you had never heard of FAP before buying your C5. Same as me, or like you, i'd never have bought this car. What can we do to inform the car buying public about the pitfalls of buying a second hand car fitted with FAP? According to web information, it is very expensive to have a main dealer re-fill the Eloys tank. So how can we warn people, presumably those on lower incomes, about the potential huge bills for this type of service? In two or three years time these cars will be priced to attract people with several kids or pensioners who need an easily accessable vehicle. Can these folk afford this £700 out of the blue?---I think not. The manufacturers have been exceptionally quiet when it comes to informing the public about this, especially those who frequently have short journeys.
Quote "pipe to replace FAP filter"--- Why could that section of exhaust not be replaced with an exhaust from a non FAP vehicle?
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Quote "pipe to replace FAP filter"--- Why could that section of exhaust not be replaced with an exhaust from a non FAP vehicle?
I can only tell you about my old C5 which was 51 reg.
This section of exhaust that contains the FAP filter has 4 sensors attached, two check the exhaust gas temperature & two check the exhaust gas pressure before & after the FAP.
These sensors report back to the ECU to tell it when to start regeneration & that regen is taking place.
So the ECU would need re-programming to ignore the FAP, a bridge too far.
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