Easier to compare when it's L/100 rather than km's per tank... some people run it to the fuel light, others only go just above "E" before classing it as "a tank"
And simply put, it depends on the type of driving you do, tune, ecu etc..... 80% of my kms are hwy... I also have an aftermarket ecu which runs closed loop (I think thats what its called!).. Basically my car is tuned to run a certain way between certain rev ranges .. so on the freeway everyday between 2900 + 3200ish rpm (110km-120km/ph) I am running an economy tune - pretty sure its at around 7L/100.. as soon as I step outside of that rev range/fuel map its back up to chewing fuel...
Everytime I fill up around the same mark, always ends up being 10L/100 (450km to 44-45L)