The final energy consumption of Indonesia's fuel oil continues to increase every year for the past ten years. In general, most of energy consumption is obtained by fossil-fuels such as oil, gas, coal, and geothermal and the rest is renewable energy. This condition indicates that Indonesia is relying on non-renewable energy sources yet, whereas the numbers are running low. To overcome it, other energy needs to be developed to replace oil fuels that are renewable, eco-friendly, and natural. One potential renewable energy source developed in Indonesia instead of fuel is bio-ethanol (C2H5OH), which is mixed with gasoline (E5, E10, and E15); further the octane value of fuel can be increased. In addition to the problems in the comparison of the two fuel mixtures, the properties of each different substance are resulted in the difficulty of mixing both types of fuel that can produce a high Coefficient of Variation which results in the performance of the gasoline engine and cause torque fluctuations (vehicle driveability problem) produced. Addition of oxygenated additives (0.5 vol %) is intended, so that an insignificant COV value will be produced (less than 10%) in the two mixtures, whereby it can enhance performance and emissions.