New help with some spring rates

[pertness]

Hi
I need some recommendations on spring rates for my coilovers,
Comes with 5F 3R but I'm thinking of upgrading to maybe 5F 4R or 5F

Any help would be appreciated thanks! :)

[cali yaris]

What coilovers are they?
What kind of driving do you do?
Why would you want stiffer rear springs?

That would help me answer your questions.