Tire with variable rolling resistance, apparatus and method therefore

The tire has a tire tread and a tire forming coating layer (1) made to contact with a bottom surface. The coating layer is formed on the supporting structure (2) filled with inflating fluid (3). A radially encircling pressure chamber (4) is provided in the bottom surface side facing away from the coating layer. The variation of the pressure of pressurized fluid (5) within the pressure chamber makes the partial region (1a) of the coating layer in the proximity of the pressure chamber to come into contact or away from ground surface. Independent claims are included for the following: (1) apparatus for varying tire rolling resistance; and (2) method for varying tire rolling resistance.