I constantly get 400-450km per 40-45 litres - its always at 10L/100 ! I only use BP ultimate or if not near a BP, Caltex (Vortex 98).
Although I do drive the freeway to & from work as well as alot of around town, cruises etc
Although the car is currently getting the last mods installed so I am waiting to see what the outcome will be on my fuel economy