Automotive sector is one of the major contributors to air pollution and global warming due to the carbon residue and smoke opacity emission. Today, the trend of decreasing sources of petroleum fuel has led to innovation of other resources such as alternative fuel. Alternative fuel can be produced from biomass such as alcohol in which it is produced by fermentation of sugar, cane and corn. This experiment was conducted to investigate the effects of ethanol on gasoline engine performance and exhaust emissions. A four-stroke, single cylinder engine was tested by different range of ethanol volume percentages i.e. 10% (E10), 20% (E20) and 30% (E30) blended with fossil gasoline. The experiment was carried out at variations of engine speed and constant load. The engine speeds used for a constant load at 2 Nm were 2000rpm, 2500rpm and 3000rpm. From the results obtained, it shows that the brake specific fuel consumption for the blended fuel is better than gasoline fuel. Combustion efficiency of gasoline engine has improved with the use of ethanol-gasoline blends. Exhaust emissions such as CO and smoke opacity are decreased due to the presence of oxygenated properties of ethanol in blended fuel. However, emissions of CO2 are increased due to the high combustion temperature. In overall, the E20 shows the best results for all measured parameters at all engine test conditions.