A device for molding and vulcanizing a tire includes an outer shell, collapsible inner support, and movable crown. The movable crown is interposed between the outer shell and inner support. The movable crown and outer shell form a cavity of controlled volume for moulding and vulcanizing, wherein the controlled volume of the cavity fits a defined volume of the tire so that the moulding pressure is maintained within a predetermined range of values. A method of moulding and vulcanizing a tire includes preparing a tire on an inner toroidal support, disposing the tire and the toroidal support in an outer shell, and molding and vulcanizing the tire. Molding and vulcanizing are carried out in a controlled-volume cavity, wherein a volume of the controlled-volume cavity increases or decreases to adapt to a volume of the tire so that the volume of the controlled-volume cavity equals the defined volume of the tire.