Originally Posted by
Siestita
"I'm a fan of liquid stoves simply because I can carry the fuel I use, and there's less waste. No half-filled steel cans everywhere. Just buy a gallon of Coleman fuel (or in your case alcohol or use HEET bottles), and use only what you need." All Down Hill from Here
I agree! And I suspect that for some solo hikers the 'break even point' when butane cooking becomes lighter than using alcohol is probably when trips last at least 6 or 7 days rather than merely 4 or 5 days.
Here's how the math looks to me. I take others' word for it that when burned petroleum products such of butane generate twice as much energy, per weight, as does alcohol. But, one ounce of alcohol fuel (measured by volume) only weighs .8 oz. (Perhaps that discrepancy reflects the fact that alcohol is lighter than water.) So, our original poster's 5 day supply of alcohol, 15 fluid oz., actually only weighs 12 oz. And, to produce an equivalent amount of heat only 6 oz. of petroleum based fuel would need to be consumed. Posters on another thread here indicated that empty fuel canisters, both large and small, weigh 4 oz, in contrast to the 1 oz. plastic bottle that I use to carry fuel alcohol. So for a hypothetical five day trip, burning 3 fluid oz. of alcohol each day, the starting weight of the fuel and its container would be 13 oz. For that same trip the starting weight carrying butane would be 10 oz. (6 oz. of fuel to burn plus 4 oz. for the metal container).
So, the total "fuel plus container" weight carried during the first day of the five day trip would theoretically be 3 oz. less if butane is burned rather than alcohol. But, as the trip progresses fuel is burned reducing a butane users' pack weight somewhat and an alcohol user's weight even more. Walking out on the last day of the trip a hiker who has burned alcohol would be carrying a "fuel plus container" weight of just 1 oz. while a butane burning hiker would be toting the full 4 oz. of his empty canister.
The example above assumes that with experience hikers can learn to take with them only the exact amounts of fuel that they will be using, thus ending their trips with empty fuel containers. I can almost accomplish that these days burning alcohol. But when I used butane stoves in the past I always finished trips carrying considerable unused fuel. And, on the trail I sometimes meet butane users who either carry a heavy extra canister with them, as a 'spare', or who have run out of fuel prematurely.
Obviously, the efficiency of one's stove/windscreen/pot support/pot configuration affects fuel usage, using either butane or alcohol. And sometimes fuel consumption can be reduced simply by altering ones cooking style or menu choices. Those factors may affect pack weight more than precisely which stove one uses.