Experimental evaluation of gasoline-hexane fuel blends usage in a spark ignition engine

In the present study, the influences of hexane addition to gasoline were researched on performance and exhaust emissions in a SI engine. It was aimed to increase engine performance and thermal efficiency of spark ignition engine. So, a single cylinder, four stroke SI engine was operated with gasoline and gasoline/hexane fuel volumetric mixtures (H10, H20, H30 and H40) at wide opening throttle (WOT) and 4000, 3600, 3200, 2800 and 2400 rpm. It was seen that engine torque and power output decreased while SFC increased with the addition of hexane in the fuel blends. Engine torque decreased by 5.69%, 7.66%, 10.80%, 14.86% with H10, H20, H30 and H40 compared to gasoline at 2800 rpm grespectively. Thermal efficiency declined by 3.27%, 7.50%, 8.95% and 11.12% using H10, H20, H30 and H40 test fuels compared to gasoline at 2800 rpm respectively. Higher CO and HC were measured with fuel blends according to gasoline for all test fuels. CO reduced by 3.77% with H40 compared to H10 at 3200 rpm. On the contrary, CO2 increased by 16.49% with H40 compared to H10 at 3600 rpm. HC increased by about 21.26% H40 compared to H10 at 3200 rpm. Although there is no positive difference on exhaust emissions and thermal efficiency is reduced, gasoline/hexane fuel mixtures can be used without modifications in SI engines.