Effect of Using Gasoline with Bioethanol on Power, Torque and Selected Exhaust Gas Components: Case Study of a Small Spark-Ignition Outboard Engine

Abstract This article presents a study of the relationship between power and torque for a small spark-ignition outboard engine depending on the fuel used. The fuels considered here were gasoline with an octane number of 95, bioethanol in pure form, and mixtures of both fuels. Also studied were selected components of the exhaust gas generated during operation of the engine for each fuel. The results showed a decrease in the power and torque with an increase in the bioethanol content of the fuel, thus confirming the possibility of using both a bioethanol additive and bioethanol itself as a fuel to power the engine. The findings of the study clearly indicate that the use of an additive in the form of plant-based fuel significantly affects the reduction of emissions of harmful substances into the environment, for example reducing CO emissions by 67%, and HC by 56%. However, without design changes to the power systems, the reduction in emissions is achieved at the cost of a drop in power of more than 30%. This topic is currently important due to the tightening of regulations on emissions and recent research and implementation by engine manufacturers related to the development of electric propulsion systems, particularly for smaller vessels. However, restrictions on their applicability result in a continued need to use internal combustion engines.