The M 25 C, part of the MaK long-stroke engine generation, is based on the proven design characteristics of the M 20 C, M 32 C and M 43 C engine series. When developing this new engine generation, the objective was to achieve a high benefit level for the customer. In all design and development considerations, therefore, three criteria had the highest priority: reliability, economy and environmental compatibility. Other points of significance in the engine's design and development work were ease of maintenance, long maintenance intervals, long component life and ease of installation.