## 3 Results
### Testing of Hourly Fuel Consumption  
Figures 5 and 6 show the effect of the additives on hourly fuel consumption. Figure 5 shows a graph illustrating the fuel consumption trend of the three cases for better clarity, for which the greatest changes occurred in order to highlight how fuel consumption changes with changing load. Figure 6 refers to fuel consumption for the three loads of the test engine supplied with fuel with additives of different concentrations. A trend graph was made for fuel without additives, for a 2% concentration of ionic silver and 5% effective liquid microorganisms. An analysis of the graph shows that the lowest value of fuel consumption was obtained for the fuel with ionic silver additives, but for these two mixtures it can be observed that as the load increases, the trend is downward compared to the consumption of pure fuel. Figure 5: Graph illustrating fuel consumption trend. It can be seen from Figure 6 that when idling, the fuel consumption was 4.7 dm\({}^{3}\)/h. At a 2% additive concentration for colloidal nanosilver and effective microorganisms in each form, there was a decrease in fuel consumption to 4.6 dm\({}^{3}\)/h. The lowest value was obtained for the silver solution, after which the fuel consumption reached a value of 4.5 dm\({}^{3}\)/h. When the concentration of the silver solution was increased to 5%, there was an increase in fuel consumption to 4.6 dm\({}^{3}\)/h. Fuel consumption with the addition of ceramic effective microorganisms was at the same level as for pure diesel fuel, while for colloidal nanosilver and liquid effective microorganisms there was an increase in fuel consumption to 4.8 dm\({}^{3}\)/h. Again, the most beneficial additive was the silver solution used at a concentration of 5%, which reduced fuel consumption by up to 4.6 dm\({}^{3}\). The consumption of fuel with the addition of ceramic effective microorganisms was the same as for fuel without any additive, i.e., 4.7 dm\({}^{3}\). At a 20 kW load, the diesel consumption without any additives was 10.2 dm\({}^{3}\)/h. With the addition of 2% liquid effective microorganisms, there was a slight increase in the fuel consumption to 10.3 dm\({}^{3}\)/h. For the other additives, the consumption decreased; for the effective microorganisms in the form of ceramic tubes it decreased to 10.1 dm\({}^{3}\)/h, for colloidal nanosilver it decreased to a level of 10 dm\({}^{3}\)/h and the largest decrease was observed for the silver solution, i.e., to 9.9 dm\({}^{3}\). At a 5% concentration there was also an increase in fuel consumption, as for idling. When the concentration was increased, the fuel consumption increased the most when liquid effective microorganisms were used, reaching 10.8 dm\({}^{3}\)/h. Colloidal nanosilver and ceramic effective microorganisms also increased the fuel consumption compared to pure diesel, to 10.5 dm\({}^{3}\)/h and 10.4 dm\({}^{3}\)/h, respectively. The smallest increase in fuel consumption relative to pure fuel and fuel with a 2% additive concentration occurred when the silver solution was used. The fuel consumption in this case was 10 dm\({}^{3}\)/h. Again, the most beneficial additive was the silver solution, which reduced fuel consumption at a 20 kW load by approximately 3%. For a 30 kW load, the fuel consumption without additives was 13.3 dm\({}^{3}\)/h. With the addition of 2% liquid effective microorganisms, there was an increase in fuel consumption to 13.5 dm\({}^{3}\)/h. The use of colloidal nanosilver caused no change and the fuel consumption remained at the same level as for pure diesel. For the effective microorganisms in the form of ceramic tubes, the fuel consumption dropped to 13.2 dm\({}^{3}\)/h. In contrast, the silver solution again proved to be the most effective, with fuel consumption dropping to 13 dm\({}^{3}\)/h after application. Figure 6: Fuel consumption for three different additive concentrations at a load of 0 kW, 20 kW and 30 kW. The 5% addition of each type resulted in an increase in fuel consumption above the value obtained for pure fuel.