## 4 Conclusions  
Despite the importance of vehicle emissions, little is known about the consequences of unregulated pollutant emissions. In the present study, we checked the ER of CO, HC, NOx, PM, NH\({}_{3}\), and organic markers emitted from gasoline, LPG, and diesel (EURO4, EURO6) vehicles using a chassis dynamometer to look into the characteristics of the pollutants emitted from vehicles. Chassis dynamometers can measure pollutant emissions from various vehicles under controlled driving conditions and can effectively evaluate emission control technology. The CO, HC, NOx, and PM emitted in regulatory test modes all satisfied the acceptance criteria. As for NH\({}_{3}\) emission in different regulatory test modes, the gasoline and LPG vehicles emitted NH\({}_{3}\) in the CVS-75 mode. The diesel vehicles emitted very small NH\({}_{3}\) amounts of 0.1 mg/km or less in the NEDC (EURO4) and WLTC (EURO6) modes. In addition, the gasoline vehicles showed characteristics where the higher the displacement, the greater the increase in NH\({}_{3}\) emission. Because the water gas shift reaction of CO generated hydrogen, which increased the probability of NH\({}_{3}\) being generated, it brought the result where NH\({}_{3}\) emission increased in the vehicles with large CO emissions. \begin{table}
\begin{tabular}{c c c c c c c} \hline  & **LPG** & **Gasoline** & **Gasoline** & \begin{tabular}{c} **Diesel** \\ **EURO4** \\ \end{tabular} & \
\begin{tabular}{c} **Diesel** \\ **EURO6** \\ \end{tabular} &
\begin{tabular}{c} **Diesel (DPFre)** \\ **EURO6** \\ \end{tabular} \\ \hline
**Compounds** & **L2 + L1** & **G1** & **G2** & **D4-1 + D4-2** & **D6-1 + D6-2** & **D6-1 + D6-2** \\ \hline
**Phthalic Acid** & 12.50 & 50.57 & 10.20 & 1512.50 & 20.10 & 30.26 \\
**Isophthalic Acid** & 2.75 & 18.09 & 2.20 & 4959.33 & 5.50 & 10.02 \\
**Terophthalic Acid** & 4.10 & 36.62 & 3.38 & 2180.72 & 6.00 & 9.50 \\
**1,2,4**-Benzene carboxylic Acid** & - & - & - & 5936.00 & - & - \\
**1,2,3**-Benzene carboxylic Acid** & 1.17 & - & - & 16,689.74 & - & - \\
**1,3,5**-Benzene carboxylic Acid** & - & - & - & 486.09 & - & - \\
**1,2,4**-Senzene carboxylic Acid** & - & - & - & 2970.78 & - & - \\ Methylphthalic Acid** & 0.96 & 5.82 & 1.38 & 683.98 & 7.17 & 10.74 \\ \hline \end{tabular}
\end{table} 
Table 10: Emission Rate of Organic Molecular Markers (Benzene carboxylic acid) (ng/km). \begin{table}
\begin{tabular}{c c c c c c c} \hline  & **LPG** & **Gasoline** & **Gasoline** & \begin{tabular}{c} **Diesel** \\ **EURO4** \\ \end{tabular} & \
\begin{tabular}{c} **Diesel** \\ **EURO6** \\ \end{tabular} &
\begin{tabular}{c} **Diesel (DPFre)** \\ **EURO6** \\ \end{tabular} \\ \hline
**Compounds** & **L2 + L1** & **G1** & **G2** & **D4-1 + D4-2** & **D6-1 + D6-2** & **D6-1 + D6-2** \\ \hline
17A(H)-22,29,30-Trisonrophane & 0.23 & 1.21 & 0.31 & 55.75 & - & 0.71 \\
17A(H)-21B(H)-30-Norhopane & 0.53 & 4.57 & 1.32 & 235.82 & 0.15 & 1.81 \\
17A(H)-21B(H)-Hopane & 0.51 & 2.20 & 0.92 & 140.73 & 0.38 & 1.07 \\
225-Homophane & 0.19 & 1.55 & 0.42 & 84.46 & - & 0.72 \\
22R-Homophane & 0.16 & 0.92 & 0.36 & 63.98 & - & 0.51 \\
225-Bishomboane & - & - & 0.35 & 49.56 & - & - \\
22R-Bishomboane & - & - & 0.37 & 37.19 & - & - \\
225-Trisonrophone & - & - & - & 30.80 & - & - \\
226-Trisonrophone & - & - & - & 18.78 & - & - \\ AAA-205-C27-Cholesterane & - & - & - & 29.84 & - & - \\ ABB-20R-C27-Cholesterane & - & - & - & 22.22 & - & - \\ AAA-208-C27-Cholesterane & - & - & - & 23.54 & - & - \\ ABB-20R-C28-Ergostane & - & - & 0.13 & 8.28 & - & - \\ ABB-205-C28-Ergostane & - & - & 0.11 & 11.23 & - & - \\ ABB-20R-C29-Sitostane & 0.13 & - & 0.16 & 26.78 & - & 0.26 \\ ABB-205-C29-Sitostane & 0.07 & - & 0.15 & 15.56 & - & 0.23 \\ \hline \end{tabular}
\end{table} 
Table 9: Emission Rate of Organic Molecular Markers (Hopanes) (ng/km). The EURO4 vehicles showed the greatest emissions of organic carbon. In addition, the difference in the organic marker substances emitted from EURO4 and EURO6 of the same fuel type was confirmed.