Tein SKM70-BUB00 High.Tech Lowering Spring for Mazda6 Front spring rate: 4.3 kilogram per millimeter (241 pounds per inch) Rear spring rate: 2.6 kilogram per millimeter (129 pounds per inch) Front ride height: -45 millimeter (-1.8 inch) Rear ride height: -29 millimeter (-1.1 inch) Progressive spring rate design