Analysing stove and fuel weight - can white gas still beat canisters?

Gear Question
1

I’ve been intrigued by the above question for a while now - the conventional wisdom is that canister gas beats white gas in both stove weight and ease of use. White gas’s only advantage is its lower cost.

But I couldn’t help but wonder - what is the fuel density of white gas compared with canister gas? Is there any chance it can beat out canisters for longer expeditions?

So I sat down and did some analysis. Let’s look at the results.

Note that you’ll obviously want some margin for error in terms of extra fuel; I have not included any in my calculations as this will vary from person to person.

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First of all, the Pocket Rocket 2 - arguably the most iconic canister stove, and still a go-to for almost everyone. The following specs are calculated based off of MSR’s website, converted to metric for ease of use.

  • Initial stove weight: 74g
  • Fuel weight: 14.175g/L of water boiled. This includes canister weight.
  • Total weight: 14.175v + 74, where v is the number of litres boiled.

Second, the Whisperlite - the go-to white gas stove for pretty much everyone.

  • Initial stove weight: 330g

  • Fuel bottle weight options:

    • 325mL: 122g
    • 591mL: 167g
    • 887mL: 218g

  • Fuel weight: 19g/L of water boiled, not including fuel bottle weight

  • Total weight: 19v + 330 + B, where v is the number of litres boiled and B is bottle weight in grams.

  • We can also calculate the density of white gas from the specs provided on the website, which is 0.964g/mL. This will be useful later.

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Looking at the analysis, things fall apart quickly for the Whisperlite. Not only is it substantially heavier, but its fuel economy per gram is worse than the Pocket Rocket - so as you carry more fuel, the Whisperlite becomes an even worse proposition.

I wasn’t done here though. I bought a Primus Omnifuel II on clearance a few weeks ago, and decided to throw that into the mix. The results were surprising to say the least.

Once again, stats are in metric, calculated directly from the manufacturer’s website.

  • Initial stove weight: 375g
  • Fuel bottle weight options:
    • 350mL: 92g
    • 500mL: 144g
    • 850mL: 213g
    • 1500mL: 279g
  • Fuel weight: 10.75g/L of water boiled, not including bottle weight
  • Total weight: 10.75v + 375 + B, where v is the number of litres boiled and B is the bottle weight.

This looks much better - the Omnifuel only consumes 11g/L of fuel, compared to the Pocket Rocket’s 14g. We can lay out some equations with bottle weights and calculate where the equations intercept each other - determining where the Omnifuel comes out ahead. We can also use the density of white gas calculated earlier to determine the maximum amount of litres a given bottle can boil.

Bottle Size Max Litres Boiled Weight Equation Intercept
350mL 31L 10.75v+467 114L
500mL 44L 10.75v+519 129L
850mL 76L 10.75v+588 150L
1500mL 134L 10.75v+654 169L
2x1500mL 268L 10.75v+933 250L

From the chart above, we see that for any of Primus’ supplied fuel bottle sizes, the amount of water you’d need to boil to break even compared to the Pocket Rocket exceeds the amount of fuel you can actually fit in the bottle.

To break even, you’d need to carry 3 litres of fuel, weighing in at a whopping 2.89 kg or 6.3 pounds, and boiling at least 250 litres of water. Add the stove weight to that and you’re carrying 3.8kg, or 8.4 pounds - just for fuel and a single stove.

To put that in perspective - boiling 8 litres of water per day, it would take 31 days to break even compared to the weight of canister fuel. Sure, maybe you’d do that faster if you’re on an expedition with 6 people - but at that point you’d want to have multiple burners, and the equation once again shifts in favor of the Pocket Rocket.

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One more thing. Let’s look at fuel costs quickly. Costs are in USD, taken directly from REI.

A single 227g IsoPro canister costs $6.95. That’s 3.06 cents/g.

A 4L jug of Coleman fuel (white gas) costs $19. That’s 0.475 cents/g.

So while canister fuel may be lighter, it is also 6.5 times more expensive. I’d analyse how much fuel you need to burn to break even on the higher cost of a white gas stove, but I’m tired of math and think I’ve done enough for one day.

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In conclusion - no, white gas cannot be more weight-efficient than canister fuel, unless you’re out for a month, or cooking for a dozen people on a single burner - which is sure to produce a lot of hangry campers waiting their turn to eat.

With that being said, white gas is far more cost-effective - it’s over six times cheaper than canister gas, and therefore definitely the best choice where weight is not a concern (car camping).

In my case, I’ll likely stick with white gas for backpacking for now; I’m not worried about carrying an extra few hundred grams of fuel, and wasting perfectly good metal after a single use instead of refilling them is not something I’m a huge fan of, given that I try to have as small a footprint on the wilderness and environment as possible (Yes, I know canisters are recyclable).

2

Whitefuel stoves are typically used in expedition/mountaineering/winter applications. Melting snow is much more energy expensive than boiling water that you get from a stream/lake in summer, and you now need to heat all the water that you drink (as opposed to relying on filtration), so daily expenditure of energy per person is going to be well in excess of what it takes to boil say 4 liters. Additionally, canister stoves start to run into problems at colder temperatures as the fuel starts to freeze as the pressure in the canister goes down, so you are no longer able to get all the fuel back from the can (and associated pressure issues are going to impact power and thus increase boiling time or even energy efficiency). So, the calculation may end up with a much earlier break point in mountaineering/winter conditions.

Finally, you don’t need to use the Primus bottles to transport fuel. You only need *1* of those bottles for running the stove, the smallest one, because it is the one you use with the pump. You can use specially designed plastic jugs which are going to be much lighter per amount of fuel they can fit.

I still use MSR PR2 or an alchohol stove mostly, weekend warrior applications fair much better with that - but in correct conditions and with better selection of equipment, you can get much better break-even points than “never because bottles are too heavy” or “month-long expedition”.

3

@Adair
Good point about the jugs; I hadn’t considered that.

I may have to do some more work on this then (energy density and energy required to melt snow would be a good place to start).

4

@Adair
That’s why I use liquid fuel, can’t remember what I have, MSR international something or other.

-30C and I’m not trusting an iso butane, though I know some wizards can probably swing it.

Don’t use it outside winter though, scares the shit out of me.

My alcohol stove is just a worse version more or less.

5

I’ve always thought of a stove like the Primus Omnifuel was something you used if you were concerned you wouldn’t be able to acquire canisters. For example if you fly to a remote location you know you can almost certainly get kerosene or similar fuel.

To me the weight of the fuel is secondary compared to convenience and the reliability of fuel acquisition. Sure it might be more expensive but then your trip could be a wash if you can’t find gas.

6

@Fay
True; if you’re in a region with easily obtainable white gas, the convenience is still a major selling point. Definitely a consideration for when traveling abroad where you can find a wide variety of fuels.

Good point about the weight; you’d be carrying a lot less if you can get the fuel along the way.

7

I think weight is generally overrated. Especially if you can burn a greater variety of fuels and have far fewer failures under extreme conditions (like cooking in freezing temps or where you can’t get the right fuel). It’s well worth the extra weight, especially for serious mountaineering or any long-duration trips in the wild.

Ultimately, it depends on your situation. If you’re traveling light for a short trip in warm weather, canisters are the easy answer. But if you’re going somewhere more remote or more extreme (like polar environments), the versatility and ruggedness of white gas stoves will serve you better.

8

@Dallas
That’s a solid perspective! If you’re not worried about light weight and are more focused on reliability in extreme conditions, then a white gas stove will make a lot of sense.

I do see how for expeditions or extended trips, the convenience of carrying canisters (if you can resupply) is often the easiest solution, though.