So now I'll tell you with some numbers how a FAP system worksRKM wrote:nope; not all of them use this fluid, although some models, such as the new Mazda CX-7 do use an additive. From memory, the CX-7 carries much more than Citroen's 5-litres - I think it was around 15.
Models, such as the Volvo V70 2.4-litre (hence a Volvo engine, not the 1.6) gets their cats hot enough, so they do not need an additive.
Eolys only reduces the temperature, at which the particles get fried. Some cars either use post-injection technology or heat the cat up electrically to "fry" the particles.
I was wondering whether Citroen adopted this later technology by the time C5 II came out.
R
To burn untreated carbon the gas temperature needs to be close to 550 deg C. normal exhaust temperature is about 170 ish.
The 2.2 regeneration cycle from inception uses post injection plus a catalyser to raise the exhaust temperature plus putting every load it can on the engine glowplugs, heated rear windows, by pass the intercooler etc. however even with all this the gas temperature only gets to around 450 -500 which is not hot enough to burn untreated carbon, the addition of Cerine in Eolys reduces the carbon burn temperature to about 450 degrees.
So you will see that Citroen had all of that technology from their first product.
For a FAP system to work without treating the carbon chemically to reduce it's burn temperature would mean having to create an exhaust temperature of around 550 degrees it's very difficult to see how that could be achieved given that PSA have used all of the techniques available to reach 450 and would I want a 550 deg exhaust I don't think so a static regen on a C5 is quite scary and will make the pitch on the road underneath soft and thats at 450 ish.
As regards face lifted C5's it is my understanding that those that have FAPS use a system very similar to that on the 2.2 but they do not use Eolys at least not the same Eolys it is a different product, the result of which is that the whole system lasts longer than that fitted on the 2.2.
as far as I know no Cit has a FAP system that does not require Eolys or a similar product, can't say for other manufacturers but the science don't change just because it's Volvo.
Finally as I have said elsewhere the FAP system has had a bad press on the 2.2 but I believe that has been due to ignorance both of the FAP system and how the wider car works. I dread to think how many FAPS have been changed just because the engine managment has come up with an "Anti Pollution" message which actually has nothing to do with the FAP.
cachaciero