2.0 HDI - Euro4 vs Euro5 vs 2.2 HDI 170ps

[10mbc]

Hello, so I'm looking for a car for long term keeping. It seems like diesels are pretty much done for the future so I would like to buy a good diesel car and keep it for a while. While I'm sure there are a lot of good diesel cars, on my short list of engines have 4 of them, all used on the Citroen C5 / Peugeot 407 / 508.
2.0 HDI 136 / 140ps - Euro4
2.0 HDI 140ps - Euro5
2.2 HDI 133ps - Euro3
2.2 HDI 170ps - Euro4

My first question is: Is there a considerable difference between the Euro4 and Euro5 2.0 HDI? Are the Euro5 more complex or do they use some more expensive accesories in order for the Euro5 norm to be attained?

Which of them should last more in time given the proper maintenance is done? Any of them have any designs flaws and should be taken off the list?

Any more information I should have before buying one of these?

Thank you!

[GiveMeABreak]

Don't forget that the Euro standards don't relate only to the engines!

The Euro standards include other standards like safety as well as environmental and emission controls. For example the 2.0 HDi 163 (DW10CTED4) is the replacement for the very reliable DW10BTED4 which as you have shown above came in 2 versions the Euro 4 and 5, however the 163 has many parts moved and relocated and modified components and a new injection system for example even though that is still Euro 5.

I would back off from the earlier 2.2 engines as they will pollute more and may cost more to run depending on legislation where you live as we go forward.

I would stick to the tried and tested ultrareliable DW10BTED4 in the 140 variant if it was me.

[10mbc]

Thanks!