Propane has about 90,000 BTUs per gallon. Gasoline has about 115,000 BTUs per gallon. And white gas (naphtha) has about 125,000 BTUs per gallon. At altitude an/or cold temps the differential grows. Another factor is the propane container feeding the stove. The 16 oz. bottles are the worst compared to a 10 or 20 pound tank. Next winter try to grill when the outside air temperature is 32* F or lower with a half empty bottle. I tried to fry fish outside an ice house on a 2 burner propane stove. Could not get the oil hot enough. My experience propane appliances are noticeably less efficient below 32* F. Even propane lanterns are much dimmer in cold weather.
