The article presents the load characteristics of the diesel D-245.7 when working on the gas-diesel process. The graphs of changes in the parameters of the combustion process, heat release characteristics, and effective indicators are given. It is important to study the issues of converting diesel engines to natural gas, as diesel engine is the most common in the national economy. The most suitable way of converting diesel engines to natural gas is to implement a gas-diesel workflow, since it does not require a significant engine rework. Diesel D-245.7 was chosen as an object of study. In the course of the study, among other things, the load characteristics of this diesel engine were removed when working on the gas-diesel process. When analyzing the experimental data obtained for a gas-diesel process as compared to a diesel one, some features can be noted. The gas-diesel process shows an increase in the temperature and pressure of gases in the cylinder. Heat dissipation is much faster. This indicates the volumetric nature of the ignition and combustion of natural gas. Engine power during the transition to the gas-diesel process is maintained at the same level, while the consumption of diesel fuel due to replacement by natural gas is reduced several times.