These manuals provide detailed operating instructions for the Doosan D1146T, D1146TI, DE08TS, and DE08TIS diesel engines. They cover essential information on the proper use and operation of the engines, including starting and stopping procedures, operational guidelines, and safety precautions. The manuals also include details on regular maintenance tasks such as oil changes, filter replacements, and system checks to ensure optimal engine performance and longevity. These documents are crucial for operators and maintenance personnel to understand and effectively manage the engines, promoting safe and efficient operation.