Internal combustion engines will be the main power for the vessels, heavy duty vehicles and thermoelectric plants in the future as it is nowadays. Finding the way to reduce environmental impact and to produce cleaner energy is the main task of engine manufacturers. In this paper, different methods and systems of diesel emission control are analyzed, especially exhaust gas recirculation (EGR) techniques that regulate emissions during their formation as well as exhaust after treatment techniques which reduce already generated harmful emissions based on the catalytic effect of precious metals, various catalytic converters and particle filtering (DPF). The problems of divergence with existing emission norms and ways of fulfilling them are also explained. The mechanism of exhaust gas formation and their connection with engine parameters were thoroughly analyzed. Problems that occurred when using individual methods for reducing emissions in specific working conditions of engines were explained. The impact of emission control systems on engine performance parameters such as fuel consumption, CO₂ emissions, load reaction and durability were explored. The experiments were performed based on failed studies of important parts within an emission control system. It was shown that only a systematic approach of solving diesel exhaust emissions with the use of advanced technologies will retain their importance and enable truly cleaner engines which will not only satisfy but well below the allowed emission norms.