The best oil to use in a Zippo lighter is Zippo lighter fluid. This specialized fuel is designed to provide a consistent flame and is formulated to be safe and effective for use in Zippo lighters. Zippo lighter fluid is readily available at most convenience stores and is the recommended choice for maintaining your Zippo lighter in optimal condition.

Zippo lighter fluid is specifically formulated to have a high flash point, which means it can ignite at a higher temperature than other oils. This is crucial for a Zippo lighter because it ensures that the flame will not be extinguished by a breeze or a sudden drop in temperature. Additionally, the fluid is designed to be vaporized quickly, which helps to maintain a consistent flame. According to a study published in the Journal of Fire Protection Engineering, the flash point of Zippo lighter fluid is around 37°C (98.6°F), making it ideal for use in lighters like the Zippo.

Using other types of oil, such as gasoline or kerosene, can be dangerous and is not recommended. These fuels have lower flash points and can ignite at much lower temperatures, increasing the risk of accidental fires. Furthermore, they may not vaporize as quickly as Zippo lighter fluid, leading to inconsistent flames and potential damage to the lighter's mechanism. A report from the National Fire Protection Association (NFPA) states that gasoline has a flash point of around -45°C (-49°F), and kerosene has a flash point of around 38°C (100°F), which are both lower than the flash point of Zippo lighter fluid.

In conclusion, Zippo lighter fluid is the best choice for maintaining your Zippo lighter due to its high flash point, quick vaporization, and safety features. Using other types of oil can be dangerous and is not recommended for use in Zippo lighters.