My 2011 Vitz

[ezhacker1]

cool sounds like you did your math. I just mean that the stiffer you go obviously the less compression you get given a fixed amount of weight (3 passengers in the rear). But the difference between say 9k and 12k is smaller than 6k and 9k. etc etc, you wont see much of a compression difference but your butt will sure feel it. 8k all around feels jolting in SF streets, and i run full soft on the shocks/struts.

At the extreme end of the spectrum of spring rate, a solid unmoveable spring = cinder block as your spring, you wouldnt get any compression, and your car will bounce everywhere. Try and find a spring height that will accomadate your drop, vs using spring rate. Of course making sure short springs will work with your shocks / struts to make sure they dont bottom out.