Canister stoves are way convenient but suffer performance in cold weather. That said, in the shoulder seasons of late fall and early spring one can use a canister stove. Keeping it warm protected in your pack and/or in your sleeping bag at night is helpful.
One issue is once used, it is difficult to determine how much fuel remains in the canister. Skip proposed weighing canisters to determine the percentage of fuel left.
Eric and I did a limited test using two full MSR IsoPro bottles, 1 partial MSR IsoPro bottle and an off brand ProFuel full bottle. The MSR bottles are labeled as 12 oz gross weight and 8 oz net weight (fuel) with a burn time of 1-2 hours.
The two MSR IsoPro bottles were measured at 12.2 oz, the ProFuel bottle weighed 10 oz, and the partial bottle weighed 6 oz.
Not much can be determined from this test. The two full MSR bottles were remarkably consistent. We need to measure an empty bottle as part of our control. One could speculate that the partial bottle has 1/3 of its fuel (and burn time) left. Has anyone any experience in weighing canisters to determine the amount of remaining fuel?