###### Abstract
In Europe, E20 is on the horizon as a means to achieving compliancy with the up-coming Euro 7 regulations. Europe is currently looking at the benefits and costs of E20 adaptation by 2030 [16]. In the literature, the impacts of different biofuel applications for engine emission reduction have been widely studied by many researchers [17; 18]. Using ethanol as a blended fuel decreases CO and HC emissions; however, it increases nitrogen oxides emissions [19; 20]. As another alternative, hydrogen has been introduced as a green fuel in recent years [3; 21]. In this concept, ammonia can be a convenient hydrogen carrier due to its high hydrogen content and availability. Ammonia could then be added as a secondary fuel in internal combustion engines for controlling the emissions and improving the combustion efficiency [22; 23]. The hydrogen and nitrogen contents of ammonia can improve combustion conditions, resulting in improved engine performance and lower fossil fuel consumption. Furthermore, as hydrogen does not contain any carbon, we can also expect a reduction in carbon dioxide via ammonia addition [23]. Besides the benefits to carbon dioxide and fuel consumption, ammonia injection can also mitigate nitrogen oxides emissions [24; 25]. [PERSON] and [PERSON] [25; 26] performed an experimental study on the injection of ammonia in a diesel engine. The results of their work showed that adding ammonia leads to an increase in engine power and a significant reduction in carbon dioxide and nitrogen oxide emissions. [PERSON] and [PERSON] [22] accomplished an experimental study on adding ammonia to the gasoline fuel of a spark-ignition engine. Based on the results of their work, the gasoline engine's carbon dioxide production rate decreased by nearly 2% by adding ammonia; however, the engine energy and exergy efficiencies decreased slightly due to the lower calorific value of the gasoline and ammonia mixture compared to pure gasoline fuel. In another study, the evaluation of ammonia's direct injection into a gasoline/ammonia dual-fuel engine was performed by [PERSON] [23]. The results of his study indicated that engine power decreased with an increase in the ammonia injection rate; however, the engine HC production rate increased significantly as the result of lower in-cylinder temperature during combustion. In dual fuel application, knock intensity is also one of the main concerns that needs to be studied when the main fuel is diluted [27; 28]. The addition of ethanol to a gasoline engine results in an increase in fuel octane number and a reduction in knock intensity in the engine, especially at high loads, as reported by [PERSON] et al. [27]. A similar work has been done by [PERSON] et al. [29] on the investigation of the impacts of methanol addition to gasoline on engine knock intensity, and it was shown that the engine knock can be improved by the modification of compression ratio and AF ratio parameters. However, there is as yet no study in the literature to investigate the impacts of ammonia injection on the knock intensity of the engine. The current literature on ammonia injection in engine applications has been predominately focused on CI engines. From the literature, it can be concluded that the injection of ammonia increases the power production and reduces the in-cylinder temperature, which leads to a reduction in thermal nitrogen oxides. Ethanol at different percentages is a common additive in gasoline fuels in many countries. So, it is important to study the ammonia injection in dual-fuel SI engines as a future alternative. Furthermore, ethanol addition showed an increase in NOx emissions in SI engines, and ammonia injection would be an efficient solution to the nitrogen oxide increment caused by ethanol addition.