Experimental study of the effect of fuel types on the performance of spark ignition engine.

Different fuels are being used daily in the city of Kirkuk, Iraq for operating vehicles with spark‐ignition internal combustion engines. Aiming to address the effects of these fuels on both engines and the environment, this work conducts an experimental study where a single‐cylinder, four‐stroke small spark ignition engine is employed. Three types of benzene with different octane ratings (low with an additive [85.8%], medium [89.2%], and high [95.6%]) are utilized in the study as they are the most consumed fuel in the area of the study. Moreover, the low‐octane fuel will be addressed with a commercial additive. In addition to engine performance, the exhaust gases and sound levels are analyzed as well. Through the outcomes, it is observed that the fuel with higher octane numbers relatively produces better engine performance and pollution. At normal engine speed, the fuel with a medium octane rating, however, has close engine performance results but with worse pollution effects. On the other hand, the engine fails to start with low‐octane fuel without the additive. The additive improves the engine performance with the low octane fuel and surprisingly produces fewer pollution gases than the fuel with medium octane number. However, the engine still behaves worse than with the other fuels at normal engine speed. [ABSTRACT FROM AUTHOR]