The use of ethanol as a fuel for internal combustion engines has been given much attention mostly because of its possible environmental and long-term economical advantages over fossil fuel. Higher carbon number alcohols, such as propanol, butanol, pentanol and hexanol also have the potential to use as alternatives as they have higher energy content, octane number and can displace more petroleum gasoline than that of ethanol. Therefore, this study focuses on improvement of different physicochemical properties using multiple alcohols at different ratios compared to that of the ethanol-gasoline blend (E10/E15). To optimize the properties of multiple alcohol-gasoline blends, properties of each fuel were measured. An optimization tool of Microsoft Excel "Solver" was used to find out the optimum blend. Three optimum blends with maximum heating value (MaxH), maximum research octane number (MaxR) and maximum petroleum displacement (MaxD) are selected for testing in a four cylinder gasoline engine. Tests were conducted under the wide open throttle condition with varying speeds and compared results with that of E15 (Ethanol 15% with gasoline 85%) as well as gasoline. Optimized blends have shown higher brake torque than gasoline. In the terms of BSFC (Brake specific fuel consumption), optimized blends performed better than that of E15. In-cylinder pressure started to rise earlier for all alcohol-gasoline blends than gasoline. The peak in-cylinder pressure and peak heat release rate obtained higher for alcohol gasoline blend than that of gasoline. On the other hand, the use of optimized blends reduces BSCO (Brake specific carbon monoxide) and BSHC (Brake specific hydrocarbon) emission with compared to the use of gasoline and E15. BSNOx (brake specific nitrogen oxides)emission of all alcohol-gasoline blends was higher than that of gasoline. However, MaxR, MaxD, MaxH reduces BSNOx significantly than that of E15. Thus, optimized multi alcohol-gasoline blends were found to be a better option in terms of fuel properties, engine performance, combustion and emission for an unmodified gasoline engine. (C) 2014 Elsevier Ltd. All rights reserved.