I get asked the question more often:
Why is the reinforced suspension spring shorter than the standard one. Does this make my vehicle lower?
Because the reinforced springs sink less after installation. If the springs were the same length as the standard springs, the car would be taller after installation.
Reinforced springs are often installed in vehicles with increased trailer operation (preferably with Bilstein B6 shock absorbers).
In addition, the price difference to the "normal spring" is usually quite small,
By the way, BILSTEIN also sells reinforced suspension springs - with the best quality.
A good investment if you often travel with a trailer or load.