I contacted Aldan Shocks to get help deciding on which coil springs to buy for my car and they told me the correct weight of spring for a car is when you have the spring loaded with the weight of the car it should compress one inch compared to the unloaded length of the spring. They said that works favorably for about every car they have worked on and you can fine tune up or down from there but said a softer ride should be brought on by softer shock, not softer spring.