A tire pressure control system for a vehicle, comprising: a supply of compressed air connected to supply compressed air to a vehicle tire through an air conduit having a valve; an air pressure sensor that senses the air pressure in the vehicle tire; a microcontroller that is connected to control the valve to supply compressed air to the vehicle tire to increase the air pressure in the vehicle tire, and to vent compressed air from the vehicle tire to atmosphere to decrease the air pressure in the vehicle tire; characterized in that: the microcontroller comprises instructions to: upon receiving a signal indicative of a required change in tire pressure from a current pressure to a target pressure, calculate a valve operation required to achieve the target pressure from the current pressure based on an algorithm stored in the microcontroller, wherein calculating the valve operation comprises calculating a length of time the valve is open to achieve the target pressure; operate the valve according to the calculated valve operation; measure an adjusted air pressure using the air pressure sensor after the calculated valve operation is completed; compare the adjusted air pressure to the target pressure and calculating a further valve operation to achieve the target pressure from the adjusted air pressure if necessary; and compare the results of the valve operation to the calculated valve operation and recalibrate the algorithm based on any differences. a supply of compressed air connected to supply compressed air to a vehicle tire through an air conduit having a valve; an air pressure sensor that senses the air pressure in the vehicle tire; a microcontroller that is connected to control the valve to supply compressed air to the vehicle tire to increase the air pressure in the vehicle tire, and to vent compressed air from the vehicle tire to atmosphere to decrease the air pressure in the vehicle tire; characterized in that: the microcontroller comprises instructions to: upon receiving a signal indicative of a required change in tire pressure from a current pressure to a target pressure, calculate a valve operation required to achieve the target pressure from the current pressure based on an algorithm stored in the microcontroller, wherein calculating the valve operation comprises calculating a length of time the valve is open to achieve the target pressure; operate the valve according to the calculated valve operation; measure an adjusted air pressure using the air pressure sensor after the calculated valve operation is completed; compare the adjusted air pressure to the target pressure and calculating a further valve operation to achieve the target pressure from the adjusted air pressure if necessary; and compare the results of the valve operation to the calculated valve operation and recalibrate the algorithm based on any differences. upon receiving a signal indicative of a required change in tire pressure from a current pressure to a target pressure, calculate a valve operation required to achieve the target pressure from the current pressure based on an algorithm stored in the microcontroller, wherein calculating the valve operation comprises calculating a length of time the valve is open to achieve the target pressure; operate the valve according to the calculated valve operation; measure an adjusted air pressure using the air pressure sensor after the calculated valve operation is completed; compare the adjusted air pressure to the target pressure and calculating a further valve operation to achieve the target pressure from the adjusted air pressure if necessary; and compare the results of the valve operation to the calculated valve operation and recalibrate the algorithm based on any differences.