A question I regularly get about Outfitting one of our home-built tent trailers is, Should I add a refillable propane cylinder or use the small disposable ones?
For me there are two primary considerations, cost and reducing waste. The cost difference is straight forward to quantify, the value of reducing waste is a personal choice.
In my area propane is going for $3.25 a gal at the local gas station. Measurement of propane is by weight, not volume. 1 gal of propane is 4.25 lbs or 68 oz. So, it works out at $3.25 a gal, it is $.048 an oz.
Around here you can pick up the Coleman 16.4 oz disposable cylinders of propane for $2.95 ea. If propane is $.048 an oz, you’re paying $.79 for the propane and $2.16 for the cylinder that you throw away.
A DOT/OPD 5 lb refillable cylinder and appliance hose runs about $66, $46 for the cylinder and $20 for the hose. So, if you’re throwing away $2.16 with the purchase of every disposal cylinder, financially you’ll break even after purchasing 30 cylinders.
So you decide which makes the most sense for you.