Miata springs come in several rate and height choices as further explained in the Miata spring product descriptions below. In general, the Progress Miata springs have proven most popular here with Miata street drivers for many years thanks to their combination of reasonable cost, mild rate increase, and mild lowering. The higher rate RoadsterSport Miata spring kits have proven most popular with the track users and customers who have the stock Bilsteins (or those adding KONI Sport shocks). We generally recommend Koni adjustable Miata shocks be matched with any of the Miata spring choices below. Our Supercharged RF shown here with KONI Sport Shocks and our exclusive Progress RF Miata Springs and 17x8 Konig Ampliform Miata Wheels.