Who can read spring rates?

[the_saint]

In my quest to find out if mazda3 lowering springs will work on a 5 I found this:
Spring rates for the Premacy
Front 2.9K
Rear 1.0-2.5K
Part# SKM18-S1B00

spring rates for the 3 (5 door hatch)
Front 2.9K
Rear 4.3K
Part# SKM66-AUB00

How does the difference in the rear effect the springs performance? Will it be stiffer or softer back there?

[RyanJayG]

the K denotes Kilograms per millimeter... so a higher number is stiffer

and just for a reference, the Tein SS coilovers for the protege (which I have) are 6kg/mm front and 5kg/mm rear.

[the_saint]

Hey, thanks for the info. Actually that's what I was suspecting (higher number = stiffer spring). I wonder why the 3 hatch has a stiffer rate than the Premacy (Mazda5)? Do you think it's just a comfort thing? Sot spring-soft ride?
I would have thought that the 5 being larger, heavier, and generally having more weight over the rear axle (presumably) would have higher rate springs in the back. (uhm)

[the_saint]

oops, I messed up. The info I found was for the first gen. Premacy and will not work on the Mazda5. (stfu)