B180 diesel - 1.5 or 1.8? How to tell&which is best?

[joropug]

Hi all,

I'm looking to buy a Mercedes B class sport, most seem to be 180ds.

I'm looking at 2012 to 14 age manuals, but in getting really confused with the engines.

Wikipedia and other sources suggest there is a 1.5 and a 1.8 variant but I'm struggling to understand how to tell the difference (in for sale adverts). Auto Trader shows displacement but not sure if it's accurate.

So I guess question 1 is when did they change it / what models is related to each engine? How do I tell?

Second is, which do I want? They seem to have similar outputs. I may consider adding a tuning box or a remap at a later date too. The 1.5 I understand is Renault derived which would put me off, if it wasn't in SO many cars. I've heard that it's a bit unrefined though.

The titles of some that I've saved so far have either cdi or cdi blue efficiency.

Third question is there are a few 200d in budget. Are these mechanically different to the 180d or can they be remapped to 200 levels?

First Mercedes so thanks for any input you can provide!

[joropug]

I'd love a 200 but there aren't many / aren't many in budget (11k).

I am a big hater of cambelts so the Mercedes engine sounds like the better choice. I wonder if there is much difference in refinement, mpg and reliability?