The usage of biodiesel has offered the planet a reassuring substitute. In addition to being a renewable energy source, it also has the potential to lessen reliance on traditional diesel fuel. Furthermore, the use of additives can help with some technical issues brought on by the use of biodiesel fuel. The variety of advantages gasoline additives provide is enormous. The combustion quality and cetane rating are improved by oxygenated additions. The most popular oxygenate additives include ethers, alcohols (including butanol, methanol, and propanol, etc.), and alcohols (such as ethyl tert-butyl ether, methyl tert-butyl ether, diisopropyl ether, dimethyl ether, diethyl ether, etc.). Among the various alcohols, ethanol and diethyl ether (DEE) are a good substitute for diesel or a way to lessen reliance on it. The outcomes demonstrated that the DEE additions improved the biodiesel's oxidation stability and cetane number while reducing its viscosity. The experiment has been carried out using a Kirloskar diesel engine under various loads. Diesel has been used as the baseline reading in this investigation. For testing, Cottonseed Methyl Ether 20% blend (B20CSME) and B20CSME + DEE with various fuel percentages (5%, 10%, and 15%) are employed. From 0% to 100% of a load was applied to the engine, and the results were evaluated, totaled, and plotted on graphs for discussion. Therefore, using this additive reduces emissions without compromising combustion characteristics.