(12 Apr 2015, 8:55 pm)DaveyBowyer wrote Are the old style E400s Euro 5 or Euro 6 if they were built and registered after 2014?
Euro 5.
I think the only vehicle in the 'Enviro' series with the possibility of retaining the old-style with the Euro 6 engine is the gas bus that Sunderland has. 28001 - 28017 are Euro 5, while 28018 - 28040 are Euro 6, though both look identical.