The Internal Combustion(IC) engine design and growth plays an important role in determining engine performance and emission features. The performance and emission properties of the spark ignition (SI) motor are also more influenced by gasoline ethanol blends. In this work, an effort has been made to optimize the operating parameters in order to minimize BSFC, CO, NO2 , CO2 , HC and maximize BTE using Response Surface Methodology (RSM). The engine is operated under constant speed conditions with different working conditions for better mixing and distinct additive composition (iso-octane) in the range of 0.3%, 0.4% and 0.5%. The appropriate RSM was used to reduce the use of petrol, its exhausts and maximize Brake Thermal Efficiency. The experimental and statistical approximation demonstrates the rise in Thermal Brake Efficiency (BTE) and decline in Specific Brake Fuel Consumption (BSFC). In addition, the chosen RSM model demonstrates reduced CO, HC, NO2 and CO2 emissions. From the assessment, it is noted that E30 mix with 0.5% additive has better motor efficiency features and reduced emissions at a peak speed of 1800rpm among all test blends with varying proportion of additives.