(10 Jun 2016, 10:26 pm)BusLoverMum wrote IIRC, the logic is that the BP branded buses get the 2 Euro 6 examples and not the red spares. And also that the taco'd buses are at an end of the fleet numbers, even if it isn't the usual one, because that bit got missed on initial preparation and despatch.
5438-5441 were originally going to be all Euro 6 but this seemed to fade away and all vehicles are Euro 5.