Majority is highway with about 100km per tank of petrol city driving (have to drive into Canberra to get petrol )
Only mods are the turboback exhaust, everything else is stock standard.
I was getting around 350km a tank when i first bought it but after changing the oil a few times it started making it past 400km a tank, a few weeks ago i changed all the filters it went up to 480km and then when i put the exhaust on i made it to 600km. No idea how it works or why it happened but it wasnt just a one off, I just filled up then and it worked out to be around 580km. These aren't full to empty readings though, its going by how many kilometers i have done (reset each fill) and how much i have to fill up to get it back to full, so unless the car uses more petrol as it gets lower it works out right. On the 600km tank i did 220km and filled up 24L, full tank is 65L, 65L/24L*220km= 595km.