# Development of a Hybrid Electric Motorcycle that
## 3 Results
### Vehicle Energy Consumption and Exhaust/Pollution Emission Experiment  
In this experiment, the average gasoline consumption and exhaust emissions of the original GRAND DINK and the HEM were compared using the settings of the ECE-40 driving mode. In the ECE-40 driving mode experiment, the actual mileage of the HEM was 1.02 km, which consumed 13.89 g of gasoline. However, the HEM was driven by the motor at low speeds; thus, electricity consumption must be included in the consideration of fuel consumption. In the ECE-40 driving mode experiment, the total electricity consumption was 16.22 Wh, which was converted into 58.392 kJ of energy. The experimental data are summarized in Table 7. The effective gasoline consumption of the HEM was calculated by Equation (1):  
\[\frac{\text{Energy consumption from electrocity}}{\text{Energy density of gasoline}}=\frac{58.392\text{ kJ}}{44.4\text{ kJ}/\text{g}}=1.315\text{ g} \tag{1}\]  
If total gasoline consumption is equal to actual gasoline consumption plus effective gasoline consumption, we can get 15.205 g. Thus, the average fuel consumption of the HEM was calculated:  
\[\text{Average fuel consumption}=\frac{\text{Actual mileage driven}}{\text{Total gasoline consumption}}=\frac{1.02\text{ km}}{15.205\text{ g}}=50.11\text{ km}/\text{L} \tag{2}\]  
On the other hand, the average fuel consumption of the GRAND DINK was calculated by Equation (3). \[\frac{\text{Actual mileage driven}}{\text{Total gasoline consumption}}=\frac{0.994\text{ km}}{25.23\text{ g}}=29.35\text{ km}/\text{L} \tag{3}\]  
The fuel consumption improvement ratio was calculated by Equation (4). The average fuel consumption of HEM minus the average fuel consumption of GRAND DINK, and then divided by the average fuel consumption of HEM multiplied by 100%:  
\[\frac{50.11-29.35}{50.11}=41.4\% \tag{4}\]  
Under the cold-start setting, the HC and CO emissions from the HEM and GRAND DINK during the ECE-40 driving mode experiment are illustrated in Figures 8 and 9, respectively. In both figures, the green curve represents the GRAND DINK while the blue curve represents our HEM. The HC and CO emissions from our HEM and GRAND DINK both increased by a similar amount during acceleration. Importantly, while the GRAND DINK had significant basal HC and CO emissions, our HEM had much lower basal HC and CO emissions. This is because our HEM was driven by the motor during low-speed driving, which significantly decreased the engine operation time. In this experimental setting, the engine operation time of our HEM accounted for only 40% of total ECE-40 testing time. \begin{table}
\begin{tabular}{c c c} \hline \hline  & **GRAND DINK** & **HEM** \\ \hline Actual driven mileage & 0.994 km & 1.02 km \\ Fuel consumption & 25.3 g & 15.205 g \\ Average fuel consumption & 29.35 km/L & 50.11 km/L \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Fuel consumption data of the HEM and GRAND DINK; HEM: our developed hybrid electric motorcycle; GRAND DINK: the ICE motorcycle manufactured by Kwang Yang Motor Co., Ltd.  
As a result, the total HC and CO emission was 184,047 ppm and 643.28% for GRAND DINK, and 76,210 ppm and 298.8% for our HEM, respectively. The improvement ratio of exhaust emissions was calculated by Equation (5). All these data are listed in Table 8.  
\[ \begin{split}\frac{\text{Emission amount of GRAND DINK - Emission amount of HEM}}{\text{Emission amount of GRAND DINK}}\times 100\end{split}  \tag{5}\]  
Figure 8: Hydrocarbon (HC) exhaust/pollution emission from our HEM (blue) and the GRAND DINK (green) after a cold start in the ECE-40 driving mode test. \begin{table}
\begin{tabular}{c c c} \hline \hline  & **GRAND DINK** & **HEM** \\ \hline CO\({}_{\text{total}}\) & 643.28\% & 298.8\% \\ HC\({}_{\text{total}}\) & 184,047 ppm & 76,210 ppm \\ CO emission improvement ratio & - & 53.55\% \\ HC emission improvement ratio & - & 58.6\% \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Exhaust emission data of our HEM and the GRAND DINK.