Is it better to exchange or refill propane tanks?

The Economics of Exchanging and Refilling Propane Tanks

While finding a provider to refill your propane tank is easy in rural areas (as many deliver), finding one in a metro area is harder. But they exist! In fact, many U-Haul rental locations offer refills. In and around cities it’s far more common for stores to offer tank exchanges – that is, you give them your empty tank and they give you a different, “full” tank.

I’ve done this for years out of convenience. There’s a chain drug store a short walk south of my home and a grocery a little farther north. Although it’s not far, I really hate lugging those heavy tanks. It’s not just the weight. They’re awkward to carry.  On my commute I frequently pass a place that offers propane refills. The thought of hauling that tank to the car, from the car to get filled and back again made me never consider it. And at $3.99 a gallon, I assumed the savings wouldn’t be worth it. I was wrong.

Most stores offering propane exchanges are deceiving you.

A 20 lb. tank doesn’t necessarily mean you have 20 lbs. of propane. I was shocked to discover that the vast majority of stores offering propane exchanges only fill them to 15 lbs. What? Yeah…really. Go check your grill. 15 lbs. too? What a racket. They do this for several reasons:

  1. Money – People don’t know they’re buying a 75% full tank. Companies make a lot more money when you have to take more trips.
  2. Liability – If you only fill something 75% full, it’s less likely someone will be able to successfully sue you based upon an allegation that you overfilled a tank.
  3. Safety – Companies who fill those tanks don’t know if they’re headed to a super hot region, or one that’s frigid cold. Since propane expands with heat, under-filling a tank is “safer”. (This is really a junk reason considering 20 lb. tanks actually hold 24 lbs., which allows for expansion in hot temperatures.)

Using Chicago-area prices, let’s see how things actually add up…

Chain Drug Store Exchange ($23.99 tank)

$23.99 / 15 lb. tank = $1.60 per lb.

Refilling Station – ($3.99 per gallon, FYI – A full 20 lb. tank is app. 4.7 gal.)

$3.99 x 4.7 gal. = $18.75        $18.75 / 20 lb. tank = $0.94 per lb.

BOTTOM LINE: Heading to a refilling station is much better for your wallet. Refilling gets you a 41% discount versus exchanging. Of course, unless you’re lucky and live close to a refilling station, you’ll have the additional hassle and expense of taking the tank there and back. As with most things, you pay a premium for convenience.

For prepper purposes, there are two other benefits of refilling versus exchanging.

First, having a completely full tank is certainly more useful in a disaster scenario than a 3/4 full tank. At a BBQ, if the gas runs out before you even flipped the burgers you just finish them inside. In an emergency situation, that fuel running out is a P.R.O.B.L.E.M.

Second, with partial refilling as an option you don’t have to wait until a tank is completely empty to get it back into fighting shape. If the electricity / heat goes out briefly and you bust into your propane stores, once things get back to normal you don’t have to sit on a partially full tank. Just go get it topped off. Of course you could exchange a partially used tank, but that’s kind of a waste of money.

One Last Tip

If you’ve decided to begin refilling the same tank rather than continuing to exchange, make sure your tank is in good condition and free of rust. Most exchange tanks have plastic wrapped all around them. In addition to being a nice big advertisement for the propane companies, they also use it to disguise rust. If you have a beat up tank it might be worth it to do one last exchange, making sure the person doing it grabs the best tank of the bunch.