What is Euro 3 an Euro 4 all about and what's the relation to a FAP?

[DirkS.]

First of all particle filters and emission classifications should be taken strictly separate. That is always one of the biggest faults being done. To get a Euro 4 rating for a Diesel passenger vehicle there is no particle filter needed! The particle threshold (Grenzwert) will be achieved without a filter anyway! So when we talk about the Euro 3/4 rating the filter does not matter in any way. So other way round fitting a filter has no influence on the emission rating of a passenger car as the filter only reduces the particle emission and not the rest of the harmful substances in the exhaust.

Next thing is about the gross vehicle weight (GVW = zulässiges Gesamtgewicht) of these vehicles. Passenger cars are classified in two big groups. Passenger cars with a GVW up to 2.500 kg and cars with a GVW above 2.500 kg. Vehicles with a GVW up to 2.5 tons have to comply with Euro 4 since beginning of this year (first registration!!!). So all vehicles which have already been registered can still comply with Euro 3 like the Eurovans. So there is no need to do anything about vehicles which have been registered before 1st of January 2006. But the manufacturers of Eurovan2 had to do something about new cars as they could not build Euro 3 vehicles after beginning of this year, as these vehicles will not be registerable in Europe! So the only way to meet the emission regulations without developping the engines to Euro 4 versions was to increase the GVW. This moved the Eurovan2 from the GVW group below 2.500 kg up to the GVW group above 2.500 kg. And this group is still allowed (until end of this year) to comply just with Euro 3. This is the trick! So changing the GVW does not change the emission rating (still Euro 3) but changes the terms and conditions for these vehicles. But decreasing the GVW, for whatever reason, is not possible as the vehicles then must comply with Euro 4 what they don't do.

And don't forget, all of the above about emission is in many cases independant from the presence of a filter!*

The filter is or better will be only interesting for environmental reasons. Personal reasons or driving bans. Perhaps for fiscal reasons but this is still not fixed and published.

So it is not a fault to have a FAP engine, as these vehicles (still independant from Euro 3 emissions) will get a sticker which allows them to drive in areas where a driving ban is going to be imposed. And the sticker has nothing to do with Euro 3 or Euro 4 (so emissions), it is only related to the particle reduction of Diesel vehicles. Which sticker it will be - there will be a certain number of them - is depending on the particle reduction rate. And this must be certified by the Eurovan2 manufacturers at any one time to get an appropriate entry in the vehicles registration documents. This entry will then qualify for getting a sticker!

*Diesel engines can be calibrated in many different ways and each way corresponds to a certain point in a curve on the NOx-particulate plot. If you regulate the engine to have more NOx you have less Particulate and vice versa. If you have a filter you can regulate the engine to have more particulate, since you will trap it, and therefore reach the Euro 4 NOx limit. Without trap, it is almost impossible with the old 2.2 and a large vehicle (you must keep into account that the 2.2 on an EV2 works harder in the test cycle than on a 407, and therefore it is more difficult to stay under the limits)

Courtesy of Klausi2306 and mggm59

Related thread: http://www.eurovan2.com/forum/eurova...-2006-a-2.html