In this study, fuel properties, engine performance, and emission characteristics of diesel fuel, false flax biodiesel, and their blends with butanol have been evaluated. Blend ratios used in this study were diesel-biodiesel-butanol (70% diesel-20% biodiesel-10% butanol and 60% diesel-20% biodiesel-20% butanol by volume) and biodiesel-diesel (20% biodiesel-80% diesel and 100% biodiesel by volume). Experiments showed that 10% alcohol addition to diesel and biodiesel fuels caused a decrease in torque value up to 8.57%. When butanol ratio raised to 20%, torque value decreased to an average of 12.7% and power values decreased to an average of 13.57%. Specific fuel consumption increased to an average of 10.63% and 12.80% with 10% and 20% butanol addition, respectively. Alcohol addiction into conventional diesel and biodiesel fuel slightly increased NOX emissions. Supplement of alcohol decreased CO and CO2 emissions when it was entrained to diesel and increased it when it was added to biodiesel. It means that addition of alcohol to diesel changed CO and CO2 emissions.