Unexpected combustions dispersion due to variations in fuel quality, production tolerance, and aging of components results in the deterioration of engine performance and increases harmful emissions. Many researchers have studied real-time combustion monitoring and control to maintain performance even under undesirable or abnormal conditions. They have reported that the reduction of combustion dispersion is promising for the decrease of emissions dispersion. In this study, we control the maximum heat release (HR) to compensate for combustion dispersion and compared the relationship between before and after control. The maximum rate of heat release (ROHRmax) is an important parameter and is highly related to engine performance and emission level. The control experiments were carried out using a diesel engine at 1500 rpm and brake mean effective pressure (BMEP) of 400 kPa, while the engine parameters were varied. The varied parameters were fuel rail pressure, swirl valve, pilot injection timing, and duration. The experimental results showed that control of the ROHRmax has the potential for the reduction of the dispersions of particulate matter (PM) emission and combustion noise even in unexpected combustion environments.