It really depends on how often you're driving and how long, plus the load. You run just above idle for most of the time (those five mile per hour speed limits are for real, and trust me, with all the chaos out there, it feels fast!) I'd test it and see. Fill up the tank, and run it dry. You need to do a test run anyway.

You need to have cans with blow off valves on them, since the gas will heat up out there. Most new cans have these built in, but check when you buy them.

--Rule number one: stay the hell AWAY from plastic containers! I had one crack open on me last year; what a mess! Go for metal cans, even if it means paying too much and getting 'em mail order. Army surplus stores sometimes carry them.

i use all kinds of gas cans, metal of course is best, old school plastic cans work too just be care full not to puncture them. the main thing with gas cans is to keep them out of the sun, i use an oil canvas tarp or i keep them under my car trailer or under the truck ( under the truck is best)
i usually bring about 30 gallons in 5 gallon jerry cans, if you get desperate you can always run to gerlach. if my art car runs out of gas, well the party's over.
good luck

Liquid Fuels

Any collection of 20 gallons or more of flammable liquid must be kept within a secondary containment area. The containment method can be as simple as a petroleum resistant tarp rolled up to provide a berm.
A supply of cat litter or fuel absorbent should be kept on hand near any spills basin.
All containers for liquid fuels must be clearly labeled identifying contents and hazards. Original labels are preferred.
A safety perimeter of 30 feet must be maintained between liquid fuel containers and any camping area, and clear access must be provided for the BRCFD in case of fire.
A sufficient amount of dry chemical fire extinguishers must be kept visible and available near the storage location of any liquid fuel.

www.burningman.com/installa...rage.html

If you have anyone in your group with a duel tank vehicle they can haul up a lot of extra fuel. we have an RV with two 30 gallon tanks. We only need to use one to get us there and back to Reno so the other we fill and just siphen (spelling???) the gas out for our camps art car. Works really well if thats an option.