## 3 Results and Discussion  
In the second stage of this study, using data from the Nissan Qashqai J10 vehicle, the AVL Cruise(tm) program was used to calculate the engine speed (Figure 8), brake torque (Figure 9), and power (Figure 10) at all WLTC driving points. The engine speed was calculated while driving in the following modes: urban cycle (I), average speed (II), and high speed (III) range from 1700 to 3800 rpm, depending on the vehicle speed and the selected gear. When driving at very high speeds (IV), the engine speed increases to 2500-4500 rpm, as the highest gear in the gearbox is five, and this gear is engaged when the vehicle speed reaches 80-90 km/h. Increasing the vehicle speed from 80 km/h to 130 km/h does not allow for a reduction in the gear ratio, and the engine speed increases by approximately 1.6 times. Replacing fuel G100 with G95H5 causes only a slight change in engine speed, as the gears are shifted identically in both cases. Engine speed is one of the coordinates in the fuel consumption and pollutant emission maps used to select the necessary parameters for WLTC indicator calculations. Figure 8: Internal combustion engine speed \(n\) during WLTC simulation: I—Urban cycle; II—Medium-speed cycle; III—High-speed cycle; IV—Very high-speed cycle. Figure 9: The brake torque \(M_{\rm B}\) of the internal combustion engine during WLTC simulation: I—Urban cycle; II—Medium-speed cycle; III—High-speed cycle; IV—Very high-speed cycle. The SIE brake torque dynamically varies at all WLTC points (Figure 9), which confirms that the engine operates in transitional modes during real driving. The load, in particular, increases as the vehicle accelerates and overcomes inertia, with the maximum value when driving at high and very high speeds approaching 140 Nm. Engine load is the second coordinate used for selecting the necessary parameters for the WLTC indicator calculations. The engine brake power directly depends on the engine speed and brake torque, and throughout the entire WLTC period, it fluctuates (Figure 10). The engine's effective power is zero when the engine is idling, or engine braking is occurring. When the vehicle is travelling at a high speed of 130 km/h, the engine load power ranges between 20 and 35 kW. During rapid acceleration, the power demand reaches 45 kW, and the engine still has a \(\sim\)45 kW reserve. Whether the vehicle is powered by G100 or G95H5 fuel, the engine brake power values at all WLTC points are similar, as the fuel type has minimal impact on engine load. The only significant influence is the increased vehicle mass due to the additional hydrogen supply system. In the WLTC test stage, the fuel consumption \(B_{f}\) data (maps) for the engine operating on G100 and G95H5 fuels (Figures 3 and 5) were uploaded into the AVL Cruise(tm) numerical simulation program. These maps were created based on the authors' preliminary experimental studies and the results of other studies [50; 51; 52]. When analyzing the instantaneous fuel consumption determined through numerical modelling, lower consumption values for G95H5 are visually observed (Figure 11). After calculating the total fuel consumption during WLTC, the fuel consumption for G100 and G95H5 was found to be 1.03 kg (44.92 MJ) and 0.92 kg (43.76 MJ), respectively. The reduction of approximately 10.4% in dual-fuel G95H5 consumption compared to G100 was due to a 6.8% higher D-F LHV (Table 1) and increased brake thermal efficiency due to the hydrogen addition. An evaluation of fuel consumption during WLTC and LHV showed that replacing G100 with G95H5 reduced fuel energy consumption by about 2.57%. The thermal efficiency of combustion increased, as hydrogen accelerated and improved the combustion process, which reduced energy loss through exhaust gasses and increased energy release due to more complete combustion. These results are consistent with other researchers [50; 53; 54].