Experimental Study of the Effect of a Non-Oxygenated Additive on Spark-Ignition Engine Performance and Pollutant Emissions

In this study, effects of adding butene, homopolymer to gasoline on the performance of a four-stroke spark ignition (SI) engine and pollutant emissions have been investigated. This additive increases the octane number of gasoline. In this research, the additive was combined with a non-leaded gasoline. Also, in addition to fuel changes and the use of additives, engine spark plugs were replaced and three types of spark plugs were used for this study. These include single electrode spark plug, dual electrode spark plug and Platinum+4 spark plug. The results of experimental tests showed that with the addition of additive to gasoline, the brake torque and braking power were increased with the use of each of the three spark plug type. The results revealed that by combining gasoline and additive, carbon dioxide and nitrogen oxides emissions were increased. On the other hand, unburned hydrocarbons and carbon monoxide emissions from the engine were reduced. In addition, it was concluded that changing the spark plugs had slight effect on engine performance and pollutant emissions, and that the results of experimental tests using all three types of spark plugs were almost identical.