Abstract
Ethanol is being used in spark ignition engines in Ethiopia for powering vehicles. The target of this research is to use the higher percentage of gasoline-ethanol blend E30 with a simple fuel system modification on a 4-cylinder 4-stroke engine on a vehicle and test its performance. The modified engine was tested for its performance with gasoline ethanol blend by varying its operating conditions and the data were recorded on exhaust emission, wheel torque, brake torque, bp, bsfc and thermal efficiency. The emission test designated that when the engine uses blends with large diameter main-jet with E30 the CO percentage was found to be lower than the gasoline. The maximum CO percent recorded on E30 was 2.8%, while the gasoline has 5.4% of CO. E30 has also recorded with maximum brake torque of 56 Nm at 1700 rpm, brake power of 16 kW at 3600 rpm and minimum fuel consumption of 576 gm/kWhr at 2800 rpm. When it was tested with gasoline its maximum brake torque was 56.5 Nm at 1500 rpm. Maximum brake power was 13.5 kW at 3300 rpm and minimum fuel consumption was 324 gm/kWhr 2800 rpm which is 25.2% lower than that of the gasoline-ethanol blend (E30). Therefore, the test result indicated reduced emission with a slight increase in bsfc for gasoline-ethanol blend (E30) fuel.