The best oil to use in a Zippo lighter is Zippo's own lighter fluid, which is specifically formulated for their products. This oil is designed to provide a consistent flame and is safe for use in Zippo lighters. The use of Zippo's lighter fluid ensures optimal performance and longevity of the lighter.

Zippo lighters are renowned for their durability and reliability, and using the correct oil is crucial for maintaining these qualities. The specialized formula of Zippo lighter fluid is designed to prevent rust and corrosion, which can occur when using other types of oil. According to Zippo's official guidelines, their lighter fluid is the only recommended fuel for their lighters. This is supported by data from Zippo's official website, which states that using any other oil can lead to performance issues and potentially damage the lighter. The company's commitment to quality and customer satisfaction is evident in their strict recommendations regarding lighter fluid usage.