The effect of ethanol blended gasoline fuels on vehicle emissions was investigated in a spark ignited single cylinder carbureted vehicle meeting Bharat Stage III (BS III) emission norms. The effect of fuel blended with 10(E10) & 20(E20) percentage by volume of ethanol; was studied on vehicular mass emissions on World Harmonized Motorcycle Test Cycle (WMTC) as well as on Indian drive cycle (IDC) without any modifications on the vehicle. These cycles are simulation of real world driving conditions. The addition of ethanol to gasoline fuel enhances the octane number of the blended fuels and increases leaning effect. It has been observed on IDC that addition of ethanol reduces CO up to 41%, THC emissions decreases by 9% and NOx reduces up to 12%. In WMTC Cycle, the CO reduces up to 32%, THC emission increases by 30%. NOx emissions on WMTC cycle decrease with the use of E10 by 6% while increase with the use of E20 by 7%. The vehicles comply with BS III Emission norms in all the fuel blends. The blended fuels decrease fuel economy by 6∼8% on these cycles owing to their lower calorific value.