A800-PSS set is designed to add 15% or 25% progressivity into the originally linear action of SPR01S and SPR01 springs in all A700/A800 cars. With the A800-PSS set the initial action of spring is softer at the beginning of the compression and becomes progressively harder when the suspension get compressed during downtravel of the car. Our tests showed that the car with PSS set at proper settings becomes more easy to drive and more consistent at low-mid traction conditions and especially on outdoor asphalt tracks.