Tein SKP30-BUB00 High.Tech Lowering Spring for Infiniti G35 Front spring rate: 5.8 kilogram per millimeter (324 pounds per inch) Rear spring rate: 4.7 kilogram per millimeter (403 pounds per inch) Front ride height: -38 millimeter (-1.5 inch) Rear ride height: -27 millimeter (-1.1 inch) Progressive spring rate design