Kumho Ecsta HS51 Autobild Test winner for BMW F31 318dA Reardrive

Hi! I’m looking for new summer tyres and see that these Kumho Ecsta HS51 should be the best according to the car picture. Have 205/16/60 on it and see that in a webshop in Croatia there is extremely cheap for 50 Euro the 205/16/55. Can they be mounted even if these 5mm are smaller? Has anyone already driven this Kuhmo Ecsta HS51? Thank you Slashchat