I want to know if they are suitable for daily driving. Are they way too stiff or acceptable? Im talking about the HKS Pro coilvers.

HKS PRO:.................672lbs(12.K).....672lbs(12.K)

 

anyone?

 

Too stiff man.. for street, you want 8kg f, 6kg rear.

 

Those might be a bit stiff for the street IMO. I am runnung 8/9 and this seems good for the crappy California roads. I don't think I could tolerate 12/12 on the roads here, but your roads might be smoother.

 

I'm running RA's at 12/10. I love it. But I am an enthusiast who loves driving my car and have no problem tolerating it.

If you think the stock stuff is stiff/bumpy, don't even bother.

Those 12K rears may beat you up though. You may want to try tuning the rear stiffness with a swaybar and softer spring to keep it more streetable.