I think it's for the best. The BlueHDi is a new engine, with improved fuel economy. Also, in the near future politicians will go after the diesel engines with new taxes and they are going to blame it on NOx emissions. The NOx EURO6 standard for diesel is very close to the one for petrol (80 vs 60 if I remember correct), unlike their difference in EURO5, so I it's possible the BlueHDi may get away with it.