I must've seen a different video?
The one I saw;
Renault:
supermarket 95 octane 81hp, BP 97 octane 81hp, Shell 98 octane 81hp
Golf:
72, 74, 77
Impreza:
235, 248, 249
Fuel octane levels as suggested in the video. (Ican't see the video linked to here, the one I saw was presented by Jon...