Nowadays, the devastating effects of the pollutants produced by gasoline are known well. As a result, scientists are looking for a better formula to replace the gasoline currently in use. Using different additives has been one of the strategies developed throughout the years. However, because certain compounds damage the environment and human life, researchers must now choose which additives to use. The primary goal of this work is to test a gasoline combination with nano-additives Ag2O and MnO2 in a 4-stroke vehicle engine (Fiat 128) and to investigate the influence of novel mixes on the efficiency of combustion rates and the amount of target pollutant gas released (CO, NOx, and the exhaust temperature). The tests were carried out at three different engine speeds: 2000, 2500, and 2900 rpm. At the end of the test, the 0.05% concentration of Ag2O nano-additive was chosen as the best sample, which increases engine performance in gasoline combustion rates and minimizes harmful gas emissions. Furthermore, CO and NOx emissions were lowered by 52% and 35%, respectively, according to EURO 6, indicating a considerable reduction in mortality rates and costs. Finally, a new mechanism was observed using Ag2O nanoparticles, leading to a reduction in CO and CO2 at the same time.