I was reading the specs on my old Coleman stove last weekend and it claims 2 hours on high with a full 16 oz canister, but I timed mine at 47 minutes boiling a pot of water at 9,000 feet near Flagstaff. Has anyone else tested the numbers on their gear and found they're off by that much?
Nodded along reading this because I had the exact same thing happen with my Jetboil last summer. I was up around 10,000 feet in Colorado and the spec sheet said 4 minutes to boil, but it took me closer to 9, and the fuel gauge dropped way faster than I expected. I started timing everything after that and now I plan for half the claimed burn time on most of my gear, especially at elevation. It's like the companies test everything at sea level with perfect temps and no wind, which is basically never how I actually camp. I've even emailed one brand about it and they just said "results may vary" which felt like a copout. Now I just carry an extra canister, better than being stuck with cold water and no way to make coffee.