You can compare the combustion characteristics of several fuels side-by-side by igniting them in smudge pots. Other containers may create the potential for explosions, so use these safe and effective containers. The only variable should be the type of fuel used; use the same smudge pot and identical equipment, including timers and temperature probes, to keep the parameters as close to identical as possible for each type of fuel. Safety comes first; read all directions carefully before conducting the experiment. As with all experiments involving heat and flames, wear protective clothing such as goggles, a flame-retardant apron and flame-retardant gloves.
Testing the duration of combustion can indicate the relative value of each as a fuel. Fuels that burn very rapidly may provide more performance to an engine, but for many uses, the performance is secondary to the amount of time it keeps the engine or other technology running. A dragster has very different needs from its fuel than does the family sedan, and a heater has different needs than a lantern. Use identical amounts of each fuel compared to keep the results valid. A variation on the experiment is to use a light meter to measure which fuels provide the best illumination at various stages of combustion.
Measuring temperature can indicate relative efficiency of each fuel. Fuels that burn hotter may be far more desirable for heating units than fuels that burn cooler. However, a peak temperature may not indicate anything; measure the temperature of each fuel several times while it is burning to establish an average combustion temperature for each. It may be interesting to use several methods of testing the temperature, or to measure the temperature of the flame from varying distances and compare the results.
A combination of duration and average combustion temperature can tell you a lot about the relative value of fuels for different applications. Using these data in chart form can answer many interesting questions, such as which fuel is best for heating applications and which is best for lighting applications.