I ran them 25psi cold on the Front and 27psi cold on the rear at the Ring but for knock hill it was 24/25psi F/R respectively.
My Fiesta does weigh just under 1000kgs now so you will possibly need an extra psi or two for the Clio.
Yes they are safe to use, Have seen it on a fair few sets of them that have been used hard Mainly on the Ring which were used again and again and they never blew up or anything:001_rolleyes:
Its not a defect, Its the way the tyres are bonded.
Federal even acknowledge this and say they arnt dangerous. I shall continue to use them when i get my Meg 250 Cup and make it track spec as well.
I run these on my Track spec MK7 Fiesta ZS and was at the Ring back in May doing 9 min laps and had zero issues with them.
Fantastic tyres IMO allowing my little 1.6 Fiesta to do laps that fast ;)