April Fuels Day

April 01 2024

"How much fuel do I need for my new backpacking stove?" is a common question at the store. Of course, the answer is "It depends." Boiling pasta for 10 minutes will use more fuel than heating water for an instant dehydrated meal, and making coffee every morning will use more fuel, too. The water and air temperatures matter, and the stove & pot selection are also factors. Let's look at the factors affecting fuel usage, how to measure your own usage, and some tips.

I usually budget 1/2 (14g) ounce of all-season isobutane fuel per person per night based on hundreds of nights with my MSR stove, weighing my fuel on every trip, and knowing that I occasionally make coffee and I most of my dinners are instant dehydrated meals. The normal range is 6-12 grams per night for me, although I burned 50 grams on a 3 night trip with temperatures in the teens, a big cooked meal one night and a hot breakfast one morning, and that was about 17 grams per night.

A simple kitchen scale will help you calculate usage according to your own habits and equipment in 3 easy steps:

1. Weigh your canister before you go to account for small production variations of a gram or two or in case the canister is partially-used. Write the weight on the canister with a permanent marker. For example, a 110g canister typically weighs 211g.

2. When you come back from your trip, weigh the canister again, and subtract the weights to calculate fuel consumption. On a recent 6-night trip, I consumed 51g, so I estimated that I had 59g of fuel remaining in this 110g canister.

3. Divide the fuel consumed by the number of nights to get the average per night. In my case, 51g over 6 nights gives me 8.5 grams per night. I used the canister again on a 2-night trip in freezing weather and consumed 21g, or 10.5g per night. The higher consumption on the second trip makes sense because of the colder weather and more usage.

My favorite camp stove setup is my MSR Pocket Rocket 2, nested inside my 900ml Toaks titanium pot with a 100/110g fuel canister. This whole setup weighs only 14.3 ounces with a full canister, including the bag for the pot, which doubles as a cozy to keep your freeze-dried dinner hot, and it is enough fuel for over a week for me. JetBoil stoves are even more efficient for very long trips, but I prefer the smaller size, lighter weight, and flexibility of this setup.

 

Which leads to my next tip: fuel may be the only backpacking equipment where the lighter option is the cheaper option. Two people out for 3 nights will normally be fine with a 100 gram canister, so why carry the heavier 200 gram canister? I admit the cost per ounce is higher, and the wider can is more stable, but it's been years since I've taken a big canister out on the trail.

Finally, you may (or may not) remember the ideal gas law (PV=nRT) from physics, and it certainly applies here. To get the last bit of fuel out of a canister with low pressure, or at low outside temperatures, you'll want to keep you canister as warm as possible. Try keeping it inside your jacket until you're ready to fire it up, and I have carefully held my hands on many canisters to warm them during operation.

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