This study analyzes the heat release rate (HRR) shape and the performance of the G95 marine engine (NOx and Specific Fuel Oil Consumption SFOC), developed by MAN En[1]ergy Solutions. The tools used for the analysis are the simulation software GT-Power and MATLAB for post-processing the results. The engine was studied in both diesel and dual fuel mode (methane main injection with a diesel pilot). For each case, the analysis was done in two conditions: - with "control on" (where parameters like maximum cylinder pressure, compression pressure, Indicated Mean Effective Pressure IMEP, and maximum injection pressure are kept fixed), and with "control off", where fewer limits are applied.