Ammonia (NH₃) has emerged as a potential carbon-free additive and alternative fuel component for internal combustion engines. When blended with diesel in compression-ignition (CI) engines, ammonia can enhance the combustion process, increase engine efficiency, and reduce carbon-based emissions. The use of ammonia as a fuel for dual-fuel combustion engines is being extensively researched in the field of internal combustion engines. This study investigated the effects of adding ammonia to diesel fuel in a boosted compression ignition engine, with ammonia proportions ranging from 10% to 90% by mass. A computational fluid dynamics (CFD) model was developed using professional GT-Power software. In this setup, ammonia was injected into the intake manifold, while diesel fuel was injected directly into the cylinder. The main output parameters measured included engine torque, power, brake thermal efficiency, and emissions of NOx, CO, CO2, and hydrocarbons (HC). The results of the study demonstrate that using ammonia as a replacement fuel at levels up to 20% can significantly reduce carbon-based engine emissions without compromising engine performance, thereby improving environmental conditions. The findings are presented and discussed in detail.