Experimental Investigation of SI Engine Performance Using Oxygenated Fuel

The current experimental study aims to examine the effects of using oxygenates as a replacement of lead additives in gasoline on performance of a typical SI engine. The tested oxygenates are MTBE, methanol, and ethanol. These oxygenates were blended with a base unleaded fuel in three ratios (10, 15, and 20 vol.%). The engine maximum output and thermal efficiency were evaluated at a variety of engine operating conditions using an engine dynamometer set-up. The results of the oxygenated blends were compared to those of the base fuel and of a leaded fuel prepared by adding TEL to the base. When compared to the base and leaded fuels, the oxygenated blends improved the engine brake thermal efficiency. The leaded fuel performed better than the oxygenated blends in terms of the maximum output of the engine except in the case of 20 vol.% methanol and 15 vol.% ethanol blends. Overall, the methanol blends performed better than the other oxygenated blends in terms of engine output and thermal efficiency.