We tested 5 different diameter pots.
We tested the boiling times for five different diameter pots varying from 78 mm (3.1 inches) to 133 mm (5.2 inches). The popular MSR PocketRocket 2 and the Soto WindMaster stove was used for testing. We measured the amount of fuel consumed to boil 1 cup of water. Each cooking pot was tested three times for each stove and then averaged.
Larger diameter pots performed better in every test.
We were surprised to learn that the larger diameter pots performed better than the narrower pots for both stoves tested. The MSR PocketRocket 2 was 43% more fuel efficient with the wider (133 mm) pot than the narrow (78 mm) pot. The Soto WindMaster, however, was only 21% more fuel efficient with the wider pot than the narrow pot.
Why does a larger diameter cooking pot perform better?
We noticed the sides of the small (78mm/3.1-inch) diameter pot became much hotter than the larger diameter pots after each boil. This suggests that the flame from the stove is warming up the sides of the pot instead of the bottom of the pot (where the greatest area of water is). The picture below shows the flame wrapping around the smaller pot when using the Pocket Rocket 2. The less efficient Pocket Rocket 2 becomes more efficient as the bottom of the larger diameter pot captures more of the heat.
Summary
- Larger diameter pots result in less fuel consumption than smaller diameter pots.
- A less fuel-efficient stove can be made more efficient by using a larger diameter pot.
The blue flame remains under the larger pot.
The blue flame wraps around the side of the smaller pot.