I have always used 98 RON, but there is a lot of factors for pingin.. My old saab 900 turbo, makes a horrible pinging on 95, even 98 sometimes..
We have alot of E85 here, basicly 85% etanol and 15% fuel, and have around 102 RON octane.. This is what I am going to run on for 35+ psi.
(uno turbo)
It had proved work just as fine as Elf turbo+ ,epensive stuff. The E85 is a lot sheaper than ordinary fuel.
We also have Shell V-power, only 99 RON, but havn´t tried it yet.