Hey,
First poster here, anyway quick history check. Just bought a 2008 Aurion SX6 drove it from Melbourne -> Adelaide, here were my stats for the trip. Note that these stats are for the average of the trip.
What fuel you use: BP Ultimate 98
How many Km's you get to a tank: no idea, assuming ~800
What your Avg 100km/L is: 7.6km/100km (at 110km/h on the highway, will go lower for downhill, higher for uphill)
What sort of driving is this based on: Melbourne to Adelaide, Highway and Great Ocean Road windy roads.
