| 摘要 |
[Purpose] To maintain a clean state of contacting portions of an internal combustion engine, remove dirt from the contacting portions of the internal combustion engine, and maintain/recover performance of the internal combustion engine. [Solution] A cleaning material for cleaning contacting portions that come into contact with lubricating oil in an internal combustion engine or maintaining a clean state of the contacting portions is disposed in a lubricating oil route of lubricating oil in the internal combustion engine and includes a fired material containing silicon dioxide and aluminum oxide as principal components. |
