Experimental Investigation of Using Gasoline–Ethanol Blends in a Spark-Ignition Engine

Abstract

The objective of this research is to investigate the effect of using unleaded gasoline-ethanol blends on the performance of an unmodified SI engine. A four stroke, four cylinders, water-cooled SI engine (type Toyota, 12 R) with a carburetor fuel system was used for conducting this study. Performance tests were carried out to obtain brake thermal efficiency, brake power, engine torque, brake mean effective pressure and brake specific fuel consumption. In these tests unleaded gasoline-ethanol blends with different percentages of fuel were implemented. Three fuels were used in the tests: 90 Octane unleaded gasoline (E-0), 95% gasoline and 5% ethanol (E-5), 90% gasoline and 10% ethanol (E-10) and 15% ethanol and 85% gasoline (E-15). Tests were conducted at one-fourth, one-eighth throttle opening positions and at variable engine speed ranging from 500 to 3000 rpm. The results showed that blending unleaded gasoline with ethanol increases the brake power, torque, and brake thermal efficiencies and fuel consumption, while it decreases the brake specific fuel consumption. The E-10 ratio gave the best brake power against speed when compared to other tests.