Propane might look like a great deal, however with only 95,000 Btu's per gallon, it is about 20% less energy per gallon than 115,000 Btu gasoline or 20% less than 135,000 Btu diesel fuel.
So the cost of $2.39 might look great compared to $3.75 gasoline, however the cost per Btu is not really all that great.
Usually you can buy propane in ever city in the United States. Not every gas station has propane fueling, however about 1 in 10 will have a propane tank. Usually they only are selling refills to 5 gallon BBQ tanks, but also sell to refill motorhome built in tanks too!
Fred.