In the context of the starlet gt turbo and starlet glanza v, our experience has shown superlows to have a softer spring rate than that of a "low" equivalent.
I have heard this to be the case with other models too but cannot confirm by first-hand experience.
We run koni adjustables and king lows in both our own cars, and run both cars quite comfortably at club tarmac and circuit events. We haven't seen justification for a coilover setup as yet.
Cheers,
Paul.
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