The paper presents a simulation of the combustion process in a dual fuel engine fueled with natural gas and diesel oil with a divided fuel dose. Diesel fuel doses – the pilot and the extra dose were injected at different times and the combustion process was different in terms of dynamics and duration. The task of the additional fuel dose was to maintain combustion, which should lead to improved engine efficiency and better ecological features. Dynamometer tests have confirmed the initial assumptions. Simulation studies have been conducted based on the original combustion model assuming different combustion of two different doses of diesel oil and natural gas. The parameters of the medium in the combustion chamber and the energy-related effect are a superposition of three separate fuel combustion processes of different combustion dynamics. The validation of the model was based on an SB3.1 engine test (engine operating under variable load and speed). Simulation studies have shown a significant effect of the initiating dose and the injection angle of the additional dose on the engine combustion parameters. The conclusions from the simulation studies can be used for the adjustment of dual fuel engines fueled with natural gas and diesel oil.