エンジン３D is a free iPhone application developed by BLOC DIGITAL LTD. It falls under the Lifestyle category and provides users with a unique way to understand the inner workings of an engine and the role of oil.

With this app, users can visually experience how oil functions inside an engine and the protective effects it has on various engine components. It aims to provide a clear and understandable depiction of the relationship between the engine's internal mechanisms and the role of oil.

Additionally, the app utilizes the latest augmented reality (AR) technology, allowing users to potentially discover an engine using their smartphones or tablets at nearby Idemitsu service stations. It provides an interactive and immersive experience for those interested in learning more about engines and oil.

Please note that this tool is designed for educational purposes and aims to visually depict concepts rather than evaluate specific oil characteristics or provide solutions.