The objective of this paper is to design static optimal control maps of diesel engines to achieve high efficiency and emission reduction. The calibration tool applied to create the control maps, named ”Off-line parameterization tool”, was designed based on the Design of Experiments method. The optimization goal is to minimize the Brake Specific Fuel Consumption (BSFC) by the engine’s input parameters under emission constraints. The tool was designed to work both fully automatically and semi-automatically. Many reports on engine calibration have taken the Design of Experiments (DoE) approach, but their implementations in choosing experimental design types and optimization processes are different compared to this paper. The unique aspect of this research lies in the significant properties of the Off-line parameterization tool. First, this tool is flexible: it is able to work with multiple inputs and multiple outputs. Second, it can reduce the calibration time as the engine running time is kept as short as possible and all the data processing work is accomplished automatically.