A personal mobility wheelchair or a scooter (300, 600, 700) comprising: a frame (210, 710a, 710b); a plurality of wheels (108, 610, 708) attached to the frame (210, 710a, 710b); one or more rotary piston pneumatic motors (140, 240, 640, 740), each of the one or more rotary piston pneumatic motors (140, 240, 640, 740) having a rotating drive shaft in operative connection with at least one of the plurality of wheels (108, 610, 708); wherein at least one of the one or more rotary piston pneumatic motors (140, 240, 640, 740) is in operative connection with at least one of the plurality of wheels (108, 610, 708) via a gear system comprising a first gear (160, 260) in operative connection with the drive shaft of the at least one of the one or more rotary piston pneumatic motors (140, 240, 640, 740) and a second gear (172, 272) in operative connection with an axle (107, 207) about which the at least one of the plurality of wheels (108, 610, 708) rotates, the gear system having a conversion ratio in the range of 1.5:1.0 to 1.0:1.5, and wherein the second gear is in operative connection with a differential; at least one tank (20, 400a, 400b, 660), for storage of a pressurized gas in operative connection with the one or more rotary piston pneumatic motors (140, 240, 640, 740) to supply pressurized gas to the one or more rotary piston pneumatic motors (140, 240, 640, 740); and a control system in operative connection with the at least one tank (20, 400a, 400b, 660) and with the one or more rotary piston pneumatic motors (140, 240, 640, 740), the control system including a flow control valve, in fluid connection with the at least one tank (20, 400a, 400b, 660) and the one or more rotary piston pneumatic motors (140, 240, 640, 740) to provide a maximum velocity of 2.7 m/s for the personal mobility wheelchair or scooter (300, 600, 700), wherein a cumulative maximum torque for the one or more rotary piston pneumatic motors (140, 240, 640, 740) is at least 16 Nm. a frame (210, 710a, 710b); a plurality of wheels (108, 610, 708) attached to the frame (210, 710a, 710b); one or more rotary piston pneumatic motors (140, 240, 640, 740), each of the one or more rotary piston pneumatic motors (140, 240, 640, 740) having a rotating drive shaft in operative connection with at least one of the plurality of wheels (108, 610, 708); wherein at least one of the one or more rotary piston pneumatic motors (140, 240, 640, 740) is in operative connection with at least one of the plurality of wheels (108, 610, 708) via a gear system comprising a first gear (160, 260) in operative connection with the drive shaft of the at least one of the one or more rotary piston pneumatic motors (140, 240, 640, 740) and a second gear (172, 272) in operative connection with an axle (107, 207) about which the at least one of the plurality of wheels (108, 610, 708) rotates, the gear system having a conversion ratio in the range of 1.5:1.0 to 1.0:1.5, and wherein the second gear is in operative connection with a differential; at least one tank (20, 400a, 400b, 660), for storage of a pressurized gas in operative connection with the one or more rotary piston pneumatic motors (140, 240, 640, 740) to supply pressurized gas to the one or more rotary piston pneumatic motors (140, 240, 640, 740); and a control system in operative connection with the at least one tank (20, 400a, 400b, 660) and with the one or more rotary piston pneumatic motors (140, 240, 640, 740), the control system including a flow control valve, in fluid connection with the at least one tank (20, 400a, 400b, 660) and the one or more rotary piston pneumatic motors (140, 240, 640, 740) to provide a maximum velocity of 2.7 m/s for the personal mobility wheelchair or scooter (300, 600, 700), wherein a cumulative maximum torque for the one or more rotary piston pneumatic motors (140, 240, 640, 740) is at least 16 Nm.