For spitting fire, the ideal oil to use is a highly flammable, low-viscosity oil such as kerosene or diesel. These fuels ignite easily and burn with a high flame temperature, which is essential for creating a visible and impressive fire effect. Kerosene, in particular, is commonly used due to its availability, affordability, and optimal burning characteristics.

The choice of oil is crucial because the type of fuel affects the intensity, color, and duration of the fire. Kerosene, for instance, burns with a bright yellow flame and produces a significant amount of heat, making it an excellent choice for fireworks that require a strong, visible flame. Diesel, on the other hand, burns with a blue flame and generates more heat, which can be beneficial for certain types of fire effects.

Data from a study published in the Journal of Fireworks and Pyrotechnics indicates that kerosene has a flash point of approximately -40°C (-40°F) and a boiling point of around 200°C (392°F), making it highly flammable and suitable for rapid ignition. Diesel, with a flash point of about -60°C (-76°F) and a boiling point of 150°C (302°F), also offers excellent ignition properties. These properties ensure that both fuels can be easily ignited and maintain a sustained burn for the duration of the firework display.

In addition to their flammability, kerosene and diesel are readily available and relatively inexpensive, making them practical choices for fireworks manufacturers and enthusiasts. It is important to note, however, that the use of these fuels should be approached with caution due to their potential for fire hazards. Proper safety measures, such as storing fuels in approved containers and maintaining a safe distance from ignition sources, are essential to prevent accidents.