Throw the compression rate of a spring we understand that if a certain weight is apply to the suspension system to compress it, and to find out how much the suspension system compress. To help us for the measuring of the rate and to shoe a permanent symbol that the entire world will recognize we use the weight over the height that means kg/m. We can create a test whit two springs, one whit a compression rate of 500g/mm and another whit 725 g/mm, this experiment will show us that if we apply a weight on the first spring of 500g/mm the first spring will compress 1 millimeter and the second spring will not compress at all. The second one needs a weight of 725 g to compress 1 millimeter.
     If we compare the two springs we can say that the first one is software and the second one is harder.
     There is other springs that have two values for reference and that are for an example: 104 kilograms until 65 kilograms and we can understand from this the next result: we need 104 kilograms for the compression of some coils and then we need a additional weight of 65 kilograms to compress the rest of the coil and the entire spring. This result helps us when we are on the road and we drive we will not exceed a certain amount of weight and only the first round of coils compress. But if we take two or three passengers along the way the second row of coils begins to be active, either way the stability of the car is the same and the handling is unchanged.

     What are the forces that affect the compression rate? That’s a simple question and we can show three important aspects.
1. First we can speak about the diameter of the steel that the spring is composed. The diameter of the spring itself effect the compression rate of the spring because if we use a bigger diameter for the springs they will become harder and that result in a harder spring to compress and that transform our suspension in a rigid way.
2. Second of all we must specify the entire diameter of the spring. Actually the entire calculation is realized with the help of the spring diameter and with the help of the coil diameter. When the entire diameter of the spring increases the compression rate drops.
3. Third of all the compression rate is influenced by the active number of the coils that enters in the composition of the spring. To determine the active number of coils from a spring we must first look at the exterior design of the spring. When the number of active coils is bigger the compression rate will increase.

     For the end we must remind we that the standard springs have an immobile compression rate from the constructors. The two step linier springs needs two undependable forces for total compression and the progressive springs have a variable compression rate.

     We must express ourselves to the idea of mounting your own springs to the car, thing that you shouldn’t do if you are not an experience mechanic. It is a tricky job and can take several hours and requires special tools. A wrong installation of the springs on the car can be easily discovered, by the simple fact that what you do whit the car, drive it. If the car has a small variable in the curves or it keeps on jumping of the road when you hit a bumper.