Like a round Rotapax would be perfect. I have found a few options which are way too expensive. I don't need anything fancy, just a doughnut shaped tank I can lower and use to fill my vehicles tank in an emergency. 5-10 gallons would probably be okay. My van is a ford transit. I have a set of 5 oversized tires so I can no longer fit my spare in the spare spot anyway. Anyone have any suggestions?