Two 35 gallon drums (vented at top) one each premium and diesel. Then another assorted 40 gallons each in Jerry cans and race cans and one gas caddy. Important thing is make sure all points of drainage are on the top of the can. Use manual or battery or electric transfer pumps. I think main danger (at least for me) would be leaks. I have gone to all top fill and dispense containers because of past concerns.