Thanks for your post! When I said 'it helps to clean the thing' I was referring to the exhaust system in general, although that wasn't clear.
The mystery continues to some degree......some PSA vehicles - even the same model for gawds sake - have Eloys, some have Adblue. This was a people carrier, 3008 or something?
Anyway - My VAG Yeti is Adblue, my PSA Bipper van has Eloys, I've just bought a spankers Honda HRV with a 1.6 diesel and that has nowt, the dealer says! All are euro 6.
When I bought the Bipper the dealer told me to only fill up when it got down to quarter tank -'so the correct amount of additive is supplied' - quote.
Who knows.
John
Oh dear - there's an essay that could be written on this!
First of all, AdBlue and Eolys do two different jobs. Eolys is there to help the particulate filter regenerate. It just lowers the temperature at which the soot particles "burn". If you have an open fire, you'll probably have noticed the back and top of the hearth are sooty, but the area right next to the coal or wood - nearest the hottest part of the fire, is clean firebrick? That's because the temperature in that part of the fire is high enough to burn the soot particles into CO2 and it just escapes up the chimney. In the diesel engine, the soot particles are caught by the particulate filter (which has a "brick" in it, a bit like a cat) and held there, in all the little grooves and tubes. After a while it starts to get choked with soot and that's when the engine management system decides to "regenerate" it - about every 500-1000 miles, typically, depending on driving style. Like the fireplace, if the engine is running hot enough, most of the soot will burn off anyway, which is why you tend not to get problems on diesels that do big motorway miles. If not, the management system alters everything it can (turbo boost, fueling, EGR valve settings, etc) to get the exhaust stinking hot for a while, during which the soot is burned and the filter is then clean and ready to accept some more. Eolys is a chemical which lowers the temperature at which the soot burns, making regeneration a bit easier. However, some manufacturers don't bother with it and just use the engine settings (sometimes squirting a bit of neat diesel into the exhaust as well, just to make it burn in there). This technology is obviously cheaper and there's less to go wrong with it, so I think Peugeot will give up on Eolys shortly. (And your dealer was talking cobblers when he was saying to fill it when it got down to a quarter of a tank! I've heard that story doing the rounds before, but we work with PSA vehicles quite a lot and none of the engineers at Peugeot had ever heard it)!
AdBlue, is there to reduce oxides of nitrogen coming out of the tailpipe. It's nothing to do with DPFs or particulates. It's a completely independent technology so you can have one without the other. Here's the interesting bit though. SOME vehicles were able to meet the emissions limits without it and others weren't. Ford, for example, on some of their small diesels, used something called a "lean NOx trap" instead of AdBlue. I imagine Honda might be doing something similar. However, this is where the plot thickens. Unlike Euro 1-5, Euro 6 comes in lots of different levels. This is largely to do with the VW scandal and the EU Commission rushing through a load of requirements that should have been "Euro 7 " when the time came, but there was a huge amount of political pressure from environmental groups and general public concerns about air quality. So we have Euro 6b (I've no idea what happened to 6a)! We then have Euro 6c, Euro 6C with a new evaporative emissions test, "Euro 6d temp" and Euro 6d (and there are a few more in between)! it's an absolute bugger's muddle, it really is! So those manufacturers who claim to be "Euro 6 compliant" without AdBlue, are probably talking about Euro 6b. As far as I'm aware, NOTHING can manage Euro 6c without AdBlue, and certainly when we get to 6d, everything diesel will not only need AdBlue, but a lot more of it than cars currently use! (The car industry is presing garage forecourts to install AdBlue pumps).
So basically, Euro 5 was the one that had particulate limits low enough to need DPFs, and the at Euro 6b, they all need DPFs, but some needed AdBlue. By Euro 6d everything diesel will need Adblue AND a DPF AND petrol engines will need "GPFs" (gasoline particulate filters). On the plus side though, we all ought to live a bit longer and fewer kids will need inhalers, so it's not all bad news!
