Tein SKJ30-AUB00 S.Tech Lowering Spring for Audi A4 Quattro Front spring rate: 5.9 kilogram per millimeter (330 pounds per inch) Rear spring rate: 6 kilogram per millimeter (174 pounds per inch) Front ride height: -39 millimeter (-1.5 inch) Rear ride height: -27 millimeter (-1.1 inch) Progressive spring rate design