EURO 2 and EURO 4, does it matter

[bloowolf]

From a functionality standpoint, Euro 2 or Euro 4 fuel will work exactly the same on a Euro 2 engine.

Euro 4 engines will need Euro 4 fuels. The reduced sulfur content from Euro 4 fuels can extend the life and efficiency of the tailpipe emissions systems that's present on Euro 4 engines.

To summarize:
Euro 2 engines can use Euro 2 and up fuels
Euro 4 engines can use Euro 4 and up fuels

Sulfur in diesel is the counterpart of lead in gasoline. It raises the cetane level & acts as a lube for the valves. It's the old, old diesel engines that are affected.