Mahua oil is a remarkable fuel since it has a similar calorific value to diesel and has similar viscosity, flash point, and boiling points to diesel. However, since mahua oil has a lower cetane number than diesel when utilized as a blend, it displays a longer ignition delay and a greater peak heat release rate, resulting in higher NOx emission. To decrease the negative impact of mahua oil on NOx emission, an effort is made to introduce the ignition improver in different proportions (i.e., 5-20% by vol). Due to its higher latent heat, IAN shows some adverse effects on performance and emission outcomes. An investigation is conducted on a CRDI engine using mahua methyl ester blended with diesel by adding oxygenated additives to the engine characteristics. The emissions like HC, CO, and smoke were reduced by 16.32, 23.56, and 23.12%. The improved combustion process increases NOx and CO2 emissions by 13.62 and 19.89%. Also, an increase in HRR and CP values was noticed at full load operation. Additionally, it is observed that the engine’s performance is enhanced using 15% Iso-amyl nitrate (IAN), indicating that the IAN blend is a useful ignition improver for mahua oil and diesel blends.