Fuels based on petroleum have been used for many years. However, as the world strives to protect the environment, clean and renewable energy is becoming more sought after. Diesel fuel can be replaced with biodiesel and alcohol. One of the advantages of these fuels is that they are renewable and locally produced. This study prepared different fuel mixes using pure Iraqi diesel as a reference and an air-cooled, single-cylinder, compression-ignition diesel engine. In this study, an experimental investigation is conducted to introduce biofuel-heavy alcohol blends as alternatives to Iraqi high-sulfur diesel. In order to produce D80B20, diesel, and biodiesel made from used cooking oil were combined. Higher alcohols (hexanol and butanol) were also added to this mixture in a 10% ratio. The engine was operated at a speed of 2500 rpm and with various loads ranging from 4 kW to 10 kW to assess its exhaust emissions. In comparison to diesel, CO levels in exhaust emissions were reduced by 29.23%, 23.59%, and 13.85%, respectively, in the tested blends, while CO2 levels were raised by 23.26%, 16.86%, and8.56%, respectively. Reductions of 25.88%, 42.35%, and 11.76%, were observed in HC concentrations. D80B10HEX10 and D80B10BU10 showed reductions of 5.7% and 3.8% in NOx emissions, while an increase of 3.5% was observed using D80B20.