Tein SKF04-AUB00 S.Tech Lowering Spring for Pontiac G8 Front spring rate: 3 kilogram per millimeter (168 pounds per inch) Rear spring rate: 6.4 kilogram per millimeter (191 pounds per inch) Front ride height: -25 millimeter (-1 inch) Rear ride height: -16 millimeter (-0.6 inch) Progressive spring rate design