A vulcanizable rubber composition comprising a) an oil extended copolymer composition consisting of i) 100 parts of at least one ethylene-α-olefin-non-conjugated-diene copolymer having - a weight average molecular weight (Mw) of at least 300,000 g/mol. - an intrinsic viscosity higher than 4, preferably higher than 4.2 measured in Xylene at 70 °C and - a polydispersity (Mw/Mn) smaller than 3, preferably smaller than 2.8, in particular smaller than 2.6; ii) 30 to 70 parts by weight per 100 parts by weight of the ethylene-α-olefin-non-conjugated-diene copolymer (i) of an extender oil and iii) up to 5 parts by weight per 100 parts by weight of the ethylene-α-olefin-non-conjugated-diene copolymer (i) of auxiliary agents, whereby the oil extended copolymer composition has a phase angle δ min of lower than 2.5, b) 1 to 15 parts by weight per 100 parts by weight based on the ethylene-α-olefin-non-conjugated-diene (i) of the oil extended copolymer composition a) of an unsaturated rubber designated as R rubbers according to DIN/ISO 1629, c) 30 to 100 parts by weight per 100 parts by weight based on the ethylene-α-olefin-non-conjugated-diene (i) of the oil extended copolymer composition a) of a filler, d) 0 to 30 parts by weight per 100 parts by weight based on the ethylene-α-olefin-non-conjugated-diene copolymer (i) of the composition a) of a process oil, provided that the total amount of extender oil from the composition a) and process oil does not exceed 80 parts by weight per 100 parts by weight based on the ethylene-α-olefin-non-conjugated-diene copolymer (i) of the composition a) and e) a vulcanizing agent. a) an oil extended copolymer composition consisting of i) 100 parts of at least one ethylene-α-olefin-non-conjugated-diene copolymer having - a weight average molecular weight (Mw) of at least 300,000 g/mol. - an intrinsic viscosity higher than 4, preferably higher than 4.2 measured in Xylene at 70 °C and - a polydispersity (Mw/Mn) smaller than 3, preferably smaller than 2.8, in particular smaller than 2.6; ii) 30 to 70 parts by weight per 100 parts by weight of the ethylene-α-olefin-non-conjugated-diene copolymer (i) of an extender oil and iii) up to 5 parts by weight per 100 parts by weight of the ethylene-α-olefin-non-conjugated-diene copolymer (i) of auxiliary agents, whereby the oil extended copolymer composition has a phase angle δ min of lower than 2.5, i) 100 parts of at least one ethylene-α-olefin-non-conjugated-diene copolymer having - a weight average molecular weight (Mw) of at least 300,000 g/mol. - an intrinsic viscosity higher than 4, preferably higher than 4.2 measured in Xylene at 70 °C and - a polydispersity (Mw/Mn) smaller than 3, preferably smaller than 2.8, in particular smaller than 2.6; - a weight average molecular weight (Mw) of at least 300,000 g/mol. - an intrinsic viscosity higher than 4, preferably higher than 4.2 measured in Xylene at 70 °C and - a polydispersity (Mw/Mn) smaller than 3, preferably smaller than 2.8, in particular smaller than 2.6; ii) 30 to 70 parts by weight per 100 parts by weight of the ethylene-α-olefin-non-conjugated-diene copolymer (i) of an extender oil and iii) up to 5 parts by weight per 100 parts by weight of the ethylene-α-olefin-non-conjugated-diene copolymer (i) of auxiliary agents, b) 1 to 15 parts by weight per 100 parts by weight based on the ethylene-α-olefin-non-conjugated-diene (i) of the oil extended copolymer composition a) of an unsaturated rubber designated as R rubbers according to DIN/ISO 1629, c) 30 to 100 parts by weight per 100 parts by weight based on the ethylene-α-olefin-non-conjugated-diene (i) of the oil extended copolymer composition a) of a filler, d) 0 to 30 parts by weight per 100 parts by weight based on the ethylene-α-olefin-non-conjugated-diene copolymer (i) of the composition a) of a process oil, provided that the total amount of extender oil from the composition a) and process oil does not exceed 80 parts by weight per 100 parts by weight based on the ethylene-α-olefin-non-conjugated-diene copolymer (i) of the composition a) and e) a vulcanizing agent.