factory weight is generally without anything, no oil, water, spare tyre etc
if its 'wet' it has all fluids, and pretty much as it would be driving on the road (not sure if they include a full tank), on oz when they are imported, they chuck them on the weighbridge, the driver stays in, all his crap etc stays in blah blah. wheels can make a difference too, plus 80L fuel=~80Kg.........