I am doing the research on fuel consumption on my car (Honda Civic FD1 2009) with different fuel type by tracking all my expenses on fuel:

Temporary:
RON 91: Full tank: 400 to 450 km (Gold Coast - Brisbane 2ways - All city drving in Gold Coast)
From 9- 10L/100 km

BP Ultimate: 450 - 500 (Gold Coast - Brisbane 2ways - City drving in Gold Coast)
From 8 to 9L/100km

At the momnet i assume that the BP ultimate give me better miles per tank. I easily to achive 6 to 7L/100km on M1 with cruise control on