The manual for the Mercedes diesel engines OM 312, OM 312 A, OM 321, OM 321 A, and OM 326 provides comprehensive information about these proven engines, which are still commonly used in shipping today. With a paperback cover and 52 pages, this work is compact yet informative. It is aimed at technology enthusiasts and professionals who wish to engage with the maintenance and operation of these specific engines. The publication, released in 2012, imparts valuable knowledge about the functioning and technical details of the engines, known for their reliability and longevity. Written in German, the manual is a useful resource for anyone dealing with the technology of Mercedes diesel engines. The first edition of this guide comes from Germany and reflects the high quality and expertise associated with the Mercedes brand.