In the current scenario of global emissions, growing demand for petroleum fuels and highly volatile crude prices, the current usage of petroleum fuel must be curbed to reduce dependence on fossil fuels and to reduce environmental pollution several alternative fuels are being explored. Butanol is one of the potential alternative fuels that can be used in IC engines in the same way of conventional fuels for reducing conventional fuels. An experimental study was conducted to establish the impact of n-butanol as a blending component for gasoline fuel in passenger car on chassis dynamometer. Commercial gasoline meeting Euro-IV fuel standards was used as the base fuel while n-butanol was used as the blending component in the ratio of 5, 10 & 20% by volume. The vehicle was tested on chassis dynamometer for fuel evaluation in respect of fuel economy, regulated and un-regulation emissions under standard driving cycle of NEDC. The results indicated that fuel economy decreased with 5% -20% n-butanol blend in range of 0.6 to 3% as compared to neat gasoline under transient condition. CO emissions increased with increase in blending ratio of n-butanol in gasoline under transient conditions whereas CO2 and NOx emissions decreased with increase in blending ratio of n-butanol in gasoline under NEDC driving cycle. Unregulated emissions such as formaldehyde and benzaldehyde decreased with increase of n-butanol in gasoline while acetaldehyde, acrolein, acetone, etc. increased. Higher blending ratios of n-butanol-gasoline were not able to be run on the vehicle with the existing setup due to misfiring/engine stalling. Overall, n-butanol can be considered as one of the promising alternative fuels for running the vehicles upto 10% and 20% without any modification of engine.