I will do most of the work myself. So labor is free for me. I will most likely run 100 liters of water per rig. I live in the desert and water is what keeps you alive. I can pack extra flats of water if we need it depending on geographical location.
Fuel will most likely be about 200 liters That should be more than enough. Not sure what these vehicles get off road but on road I believe 15 liters/100km is about right.? I would like to go at least 800 miles or 1287 km. Cut that in half for a loaded expedition rig off road in the sand/mud nets you 400 miles or 644 km of your lucky. Water and Diesel are always the heaviest consumable items on any expedition rig. The trick is to stay under your Gross Vehicle Weight. 200 liters of diesel is about 170 kilos not including the tanks of course. Back packer food is pretty light as well as the hiking gear needed to heat it up and boil water etc. I can save weight there. Also as the days go on the vehicle gets lighter and lighter as the fuel and water are consumed.
My concern for the extra fuel capability is for the Simpson Desert crossing. Not much fuel for days from what I have read so far. The Cape York Track has enough fuel stations close enough that I won't have to fill one tank up all the way. I would have the rear most tank with the least amount of fuel in it for that track. The water tanks will be behind the front seats bolted down in the bed to keep the weight distribution more even. Those I won't need to have filled nearly as much as I would for the Simpson Desert crossing. 100 liters of water will last 2 people about 10 days. Of course that is the worst case scenario. I do not plan on crossing The Simpson in the middle of your summer so it may be a bit much.
Of course I will need to balance everything out to stay under the Gross Vehicle Weight rating. Thats 3400 kilos. I have 1000 kilos to work with. Of that I want to come in at about 800 kilos. This has always been a THE challenge for Explorers and other Vehicle based Expeditions. If Ernest Shackleton had the chance to do it all over again I am sure he would have found a way to carry more supplies.
Thanks for your help. I do need to watch the weight I put in her. It all adds up pretty quick. I am sure when Im on the ground and weighing everything out that I will indeed need to cut my list shorter than it is now. My hope is as I install the stronger components that they pretty much cancel each other out. Not entirely but pretty close. Then again adding a power steering system will add more weight. My greatest challenge will be to limit the amount of clothes my wife a daughter bring!

