The present invention provides a tire pressure regulation system for use in a pneumatic tire mounted on a vehicle to continuously maintain a predetermined optimum pressure by automatically inflating or deflating the tire as needed. The system employs one or more actuators, an air pump pneumatically coupled to the tire and a motion reversal device coupling the actuator and the piston of the pump. The actuators are controlled by the tire pressure in one direction and the tension of one or more springs in the other direction. The springs are attached to the handle of the piston at one end and the body of the pump at the other end to provide the appropriate tension to maintain the optimum pressure in the tire. When the tire pressure is low the pump piston is pulled out. The piston pumps air into the tire when the pulled out pump piston is pressed against the road while the vehicle is in motion. A separate rod coupling the piston handle and a valve in the tire is also provided to deflate the tire when the tire pressure is higher than a predetermined high pressure value.