Having made extensive enquiries regarding replacement springs for my 5-door Abarth I have been reliably informed that UNDER NO CIRCUMSTANCES should the JTD springs be fitted to the 2.4.
They are the same size and will fit but are made to a DIFFERENT COMPOUND and are not suitable for the heavier and sportier Abarth!

Excellent! That's another myth sorted then

That's a question that gets asked regularly on here so that's useful info

Hmmm I'd be very surprised if the Abarth lump was any heavier than a turbodiesel. And I bet the torque output of the JTD well exceeds the Abarth...

From the Owner handbook.

Max admitted load on front axle

2.4 1030kg
1.9 JTD 1020kg

1% heavier so there must be more to it than that.

The info came from Mick at shop4parts. He contacted Bosch, I believe, and that's what they told him. Also there is a company selling springs for the 2.4 Stilo which are not compatible with the Abarth because they are not Sports springs. So I assume that it's not just the weight but also the extra power, cornering etc.

What do Bosch know about springs?

They are a supplier that shop4parts use, they do rear springs apparently but not the front. Maybe it was a different manufacturer he asked but, anyway, that was the conclusion.

How much are std springs per set ?
I fitted eibachs years ago and never regretted it , at the time im sure they were closer to £120-£130 seem to have gone up a bit now.
http://www.dcperformance.co.uk/uprated/eibach-pro-kit-springs/fiat/stilo.html
You can see how eibach group them.
The abarth bit not mentioned , but the 20v 2.4 is grouped with likes of mine which is jtd 16v sporting and im sure equally sporty to abarth.
Std springs no idea , but with the reputation for snapping id never fit a std spring.