Quote Originally Posted by the evil twin View Post
Trip computer?
and...
V8 Falcons don't weigh anything like a 'Trol or have the aeros of a brick.

You need to get the accurate K's (given 33's mean you actually travel further than your Odo states) and accurate litres used.
You can expect anything between 10 and 16 LPH depending on terrain, wind, auto/manual and driving style.
Most will average between 12 and 15 LPH on the bitumen anything over that is starting to get excessive
I'll do some calculations after a nice drive this weekend after I remove the rack and check the tyre pressure. I'll fill the tank and hit the road....