In this study, experimental tests were carried out to improve the performance and emission characteristics of the diesel engine as amyl alcohol (pentanol), which is in the heavy alcohol class, obtained from the residual waste from etha-nol, which is produced as a by-product during sugar production from sugar beet. Tests were performed on naturally aspirated, air-cooled, four-stroke, single cyl-inder, direct injection, 6LD 400 Antor diesel engine at full load and engine speeds of 1400, 1700, 2000, 2300, 2600, 2900 and 3200 rpm. Pure diesel and fuel mixtures containing 5%, 10% and 20% amyl alcohol were used in the exper-iments. As a result of the experiments, while the power and torque values de-creased, the brake specific fuel consumption (BSFC) value increased as the ratio of amyl alcohol in the mixture increased compared to diesel fuel. In addition, the increase in amyl alcohol ratio in the mixture decreased hydrocarbon (HC), car-bon monoxide (CO), and smoke emissions, while increasing carbon dioxide (CO2) and nitrogen oxide (NOx) emissions. With 20% amyl alcohol ratio, an in-crease of 30.324% in BSFC value and a decrease of 13.745% and 10.258% in power and torque values were found as the average of all speeds, respectively. When evaluated in terms of emissions, with 20% amyl alcohol ratio, an average reduction of 44.565%, 42.832% and 27.330% was achieved in HC, CO, and smoke emissions, respectively, while NOx and CO2 emissions in-creased by 15.520% and 54.934%, respectively.