Inadequate, non-professional, or inexperienced maintenance significantly accelerates the aging and degradation of diesel engines. Poor maintenance leads to faster wear, undetected faults, and decreased reliability due to improper repairs or adjustments. Using a single engine type for a fleet can mitigate these issues by simplifying training, reducing maintenance costs, standardizing procedures, and allowing technicians to develop deep expertise in maintaining that specific engine type. This approach enhances operational efficiency, reliability, and cost-effectiveness, ensuring the longevity and performance of the engines.