Specific consumption: This is the most useful criterion for determining how much fuel a stove is likely to consume. Specific consumption is defined as the amount of fuel it takes to perform a specific task, for example, the amount of fuel consumed per litre of water boiled or food cooked. Turn down ratio: This is also known as control efficiency, determined by the difference in fuel consumption per minute between high power (bringing water to a boil) and low power (simmering). Stoves with a higher turn down ratio are likely to use less fuel during a real-life cooking task, which involves bringing food to a boil and then cooking it.
