## 3 Experimental Results and Discussions
\begin{table}
\begin{tabular}{l c c c c} \hline \hline  & **Vehicle Mass** & **Vehicle Mass** & **Vehicle Mass** & **Vehicle Mass** \\  & **1566 kg/** & **1462 kg/** & **1484 kg/** & **1526 kg/** \\  & **115,477 km** & **134,141 km** & **134,141 km** & **134,141 km** \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline  & & & & \\ \hline \hline \end{tabular} _Notes: The braking difference was measured by the distance traveled from the moment of braking (against a well-established landmark) until the complete stop of the vehicle. The values of braking distance difference, service brake efficiency, and parking brake efficiency are not whole values (whole numbers) but have been rounded to whole values (that is, to higher values)._  
\end{table} 
Table 4: Braking system efficiency according to the mass variation for two values of the driven km of the vehicle. Therefore, from the analysis of the results of experimental tests carried out on a vehicle both with used discs and pads, as well as with new discs and pads, it was found that the \begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & **Braking System** & \begin{tabular}{c} **Minimum** \\ **Allowed Limit for** \\ **the Efficiency, \%** \\ \end{tabular} & \begin{tabular}{c} **Vehicle Speed,** \\ **km/h** \\ \end{tabular} & \
\begin{tabular}{c} **Braking Time,** \\ **Distance, m** \\ \end{tabular} &
\begin{tabular}{c} **Braking Time,** \\ **s** \\ \end{tabular} \\ \hline \hline \multirow{3}{*}{Brake system with worn discs and pads} & \multirow{3}{*}{59} & \multirow{3}{*}{43.5} & 25 & 1.38 & 1.21 \\ \cline{3-5}  & & & 40 & 4.26 & 1.89 \\ \cline{3-5}  & & & 50 & 5.44 & 2.46 \\ \cline{3-5}  & & & 25 & 1.31 & 1.17 \\ \cline{3-5}  & & & 40 & 3.92 & 1.74 \\ \cline{3-5}  & & & 50 & 5.14 & 2.20 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Average values of the braking distance and time, respectively, and the braking system efficiency and the vehicle speed. Figure 11: Braking system efficiency evolution the according to the vehicle mass variation and driven km. \begin{table} \begin{tabular}{l c c c} \hline \hline  & **Vehicle Mass 1566 kg/** & **Vehicle Mass 1526 kg/** & **Vehicle Mass 1484 kg/** \\  & **115,477 km** & **134,141 km** & **139,334 km** \\ \hline \hline \multirow{3}{*}{Braking difference of the service brake, m} & \multirow{3}{*}{5} & \multirow{3}{*}{5} & \multirow{3}{*}{12} \\ \cline{3-5} Service brake efficiency related to the vehicle’s total mass, \% & & & \\ \cline{3-5} Parking brake efficiency of the related to the vehicle’s total mass, \% & & & \\ \hline \hline \end{tabular} 
\begin{tabular}{l c c c} \hline \hline  & _Observations:_ Notes after Table 4 are also valid for Table 5—respectively, the methodology for calculating service and parking brake efficiency is similar and is also based on the relation/Equation (1), for example: \(\eta_{x}\), \(\%_{x}=\frac{Total\text{ braking force on the axis}}{\text{Volision (1484)}}\times 100\) \(\approx\) 73 \%\(\%\), respectively, \(\eta_{x}\), \(\%_{x}=\frac{Total\text{ braking force on the axis}}{\text{Volision (19.64-160)}}\times 100\) \(\approx\) 24 \%\(\%\). As mentioned, the braking force values of the service brake are 10.70 (6.81 + 3.89) kN for /1566 kg/115,477 km: 8.88 (5.62 + 3.26) kN for 1526 kg/1341 km; 10.80 (6.96 + 3.84) kN for 1484 kg/139,334 km. And those of the parking brake are 3.60 (2.05 + 1.55) kN for 1756 kg/115,477 km; 2.89 (1.68 + 1.21) kN for 1526 kg/134,141 km; 2.56 (1.96 + 1.60) kN for 1484 kg/139,334 km and were also measured on the dynamometer stand.