1. You don't burn liquid propane, you burn the gas that "Boils Off" the liquid.
2. The surface area of the tank dictates the ability of a system to handle a load. (larger surface area = larger supply of gas)
3. Driving down the road causes the liquid to slosh in the tank. This problem is exaserbated my an upright tank.
4. Propane "Boils" at -44 degrees F.
5. Propane is Twice the weight of air as a gas.
6. Propane is Half the weight of water as a liquid.
7. Propane is odorless. (the odor is added, kinda like inviting your brother in law over) The smell is worse as the tank empty's as the odor settles to the bottom of the tank.
8. Propane contains roughly 99,000 BTU per gallon. (handy to figure how long a tank will last ie 1 gal of propane will burn 3 hours in a 33,000 BTU furnace on high, roughly)
These facts are offered as general info and from the foggy mind of an ever ageing guy, take them as such. Bagger