INVESTIGATION OF THE EFFECTS OF GASOLINE – ETHANOL FUEL BLEND ON THROTTLE RESPONSE AND INTAKE AIR TEMPERATURE IN A NATURALLY ASPIRATED S.I. ENGINE

Ethanol-gasoline fuel blend is the most encouraging substitute to the gasoline fuel for all new generation spark ignition (S.I.) engines. By the adding ethanol which is oxygenated in nature, a higher level of oxygen and octane rating is achieved, which in turn increases the volumetric efficiency and combustion efficiency of the naturally aspirated S.I. engine, with a reduction in heat loss after the combustion, as compared to the pure gasoline driven engine. In this research paper, we investigated the effect on throttle response of naturally aspirated S.I. engine and the variation of intake air temperature due to the engine heat loss by using ethanol blend (E0, E10, E20, and E30) in real driving conditions with the aid of a Launch C Reader VI code engine scanner. The result shows that the blending ratio has a direct impact on the fuel efficiency of the vehicle which was enhanced from 18.6 to 24 km/L respectively for E0 to E30. The throttle response at low speed is also improved in terms of achieving higher engine speed (~2000 rpm). A throttle valve opening of 11.2% is required in the gasoline driven engine while only 9.6 % is required in E30.