An air suspension system comprising: at least one air spring assembly including a piston airbag and a primary air bag mounted around said piston airbag; a valve assembly that controls air supply into and out of said piston airbag; and a controller the system including at least one pressure sensor that continuously measures pressure within said piston airbag, said pressure sensor generating a pressure signal that corresponds to a measured pressure; wherein the controller receives said pressure signal as an input, compares this input to at least one desired piston airbag characteristic, and generates an output signal to modify pressure within said piston airbag if said input is different from said desired piston airbag characteristic, and said controller receives a plurality of driver inputs and a plurality of vehicle inputs, and wherein said controller determines a compensated target pressure for said air spring assembly based on said inputs and determines whether piston airbag pressure should be adjusted based on the compensated target pressure; wherein the at least one desired position airbag characteristic comprises a desired piston air bag diameter to provide a desired spring stiffness, wherein at least the air spring pressure and suspension position are communicated to said controller as one of the inputs, wherein said controller generates piston pressure compensation data based on at least the air spring pressure and suspension position, generates a corner force command that is mapped to piston pressure to provide a force to piston pressure determination, and determines the compensated target pressure based on the force to piston pressure determination and the piston pressure compensation data, and wherein said controller generates a control signal to exhaust or supply air to the piston airbag based on the compensated target pressure, and actively adjusts pressure within the piston airbag in response to pressure changes within the piston airbag to maintain the desired spring stiffness in a closed loop manner. at least one air spring assembly including a piston airbag and a primary air bag mounted around said piston airbag; a valve assembly that controls air supply into and out of said piston airbag; and a controller the system including at least one pressure sensor that continuously measures pressure within said piston airbag, said pressure sensor generating a pressure signal that corresponds to a measured pressure; wherein the controller receives said pressure signal as an input, compares this input to at least one desired piston airbag characteristic, and generates an output signal to modify pressure within said piston airbag if said input is different from said desired piston airbag characteristic, and said controller receives a plurality of driver inputs and a plurality of vehicle inputs, and wherein said controller determines a compensated target pressure for said air spring assembly based on said inputs and determines whether piston airbag pressure should be adjusted based on the compensated target pressure; wherein the at least one desired position airbag characteristic comprises a desired piston air bag diameter to provide a desired spring stiffness, wherein at least the air spring pressure and suspension position are communicated to said controller as one of the inputs, wherein said controller generates piston pressure compensation data based on at least the air spring pressure and suspension position, generates a corner force command that is mapped to piston pressure to provide a force to piston pressure determination, and determines the compensated target pressure based on the force to piston pressure determination and the piston pressure compensation data, and wherein said controller generates a control signal to exhaust or supply air to the piston airbag based on the compensated target pressure, and actively adjusts pressure within the piston airbag in response to pressure changes within the piston airbag to maintain the desired spring stiffness in a closed loop manner.