Tall oil is a waste energy source that can be called as the extract of trees that emerge in paper mills. Fusel oil is a sugar molasses process waste which is a waste alcohol combination of high molecular alcohols. In this study, tall oil acids were mixed with 20% by volume of diesel fuel and alcohol (ethanol, methanol, isopropyl, n-butanol and fusel oil) were added to the same ratio and their effects on combustion, fuel line pressure, engine performance and emissions were investigated. The mixtures were tested by using a single-cylinder engine with compression-ignition, direct injection at constant engine speed (1800 rpm) and 2 Nm, 4 Nm, 6 Nm, 8 Nm engine torques. With the use of fuel mixtures, in-cylinder pressure values decreased in all conditions compared to D100 fuel. The highest drop in in-cylinder pressure values is 7.1% with DT20M20 fuel mixture. Fuel mixtures were found to be sprayed earlier than the injector compared to diesel fuel. BSCF the highest rate of increase was seen with the DT20M20 fuel mixture at 9%. All fuel mixtures have been found to produce reduction in CO and smoke opacity emissions and an increase in HC and NOx emissions. With D100 fuel, emission values measured at (CO) 0.35 ppm and (is) 46%, respectively, decreased to (CO) 0.24 ppm and (is) 33% with the DT20I20 fuel mixture under the same conditions. The highest NOx emission was 14.8% with DT20I20. HC emission using the DT20M20 fuel mixture was determined to be 83 ppm.