## 4 Results and Discussion  
### Measurement Results with Hatchback  
The measurements with Hatchback were performed to calculate the position of the center of gravity in the horizontal direction as well as in the vertical direction. The observed values of its axle loads are given in Table 3. The weight of two iron beams with two pallets was subtracted from the measured weights, and it was 166.5 kg (Figure 1). When measuring with the lifted axle (Figure 3), 6 pallets were used, and the weight of beams with pallets was 246.5 kg. Based on the change in the weight applied to the front axle when the vehicle is in the plane and the front axle is lifted (Table 3, comparing the columns 2 and 4), the change in the center of gravity's height can be estimated as well. The higher the difference in the weight applied to the front axle, the higher the center of gravity [74]. To verify the measurement accuracy, Table 4 shows the calculated measurement deviations. The second column shows the vehicle mass given by the addition of the weight applied to the front and rear axles in the plane (Table 3, Columns 2 and 3). Column 3 shows the theoretical vehicle mass, i.e., the addition of the weight of the empty vehicle with the driver, and separately weighed mass of the load and roof box according to a particular measurement variant. The theoretical mass is considered as \"actual weight\" since there is an assumption of smaller deviation when weighing the vehicle and load separately, also bearing in mind that one scale division of the pallet truck's scale is 0.5 kg. Thus, the percentage expression of the difference between the \"Measured vehicle mass\" and the \"Theoretical vehicle mass\" can be considered as a measurement deviation as well as a deviation for further determining the center of gravity's position since the weight applied to the axles is the most important value for the calculation of the center of gravity's position. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Variant** & **Front Axle (kg)** & **Rear Axle (kg)** & **Lifted front Axle (kg)** \\ \hline Empty vehicle & 789.0 & 516.5 & 768.5 \\ Load in the luggage compartment & 776.5 & 734.5 & 745.5 \\ Load on the rear seats & 827.5 & 684.0 & 804.0 \\ Load in the luggage compartment and in & 806.0 & 716.0 & 773.5 \\ Load in the roof box only & 815.0 & 573.0 & 788.5 \\ Load on the rear seats and in the roof box & 841.0 & 681.5 & 807.0 \\ Load on the rear seats, empty roof box & 831 & 692 & 800.5 \\ Load in the luggage compartment, empty & 778 & 745 & 748.5 \\ Empty vehicle, empty roof box & 792.5 & 524.5 & 771.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Measured values of hatchback. As follows from Table 4, there were very low measurement deviations. The highest measurement deviation was with the load in the roof box, i.e., 0.50%. In the other cases, there was very high measurement accuracy achieved, as it is possible to consider weighing of the vehicle separately and weighing the load separately to be an \"etalon\". Thus, the basic and the most important condition for determining the center of gravity's height and for determining the vehicle mass as close as possible can be regarded as fulfilled. The mass divided into the front and rear axles and given in percentage is shown in Table 5. Table 5 also shows the distance of the center of gravity from the front and rear axles of the Hatchback, L1 and L2, calculated according to Formulas (1) and (2). The last column shows the calculation of the change in the distance of the center of gravity from the front axle in comparison with the empty vehicle. To compare with the empty vehicle, it led to the most substantial change in the axle load when unloading the whole load into the luggage compartment, and the roof box was empty, with a difference of about 9%. Such a change in the axle load and reduction of the load of the front driving axle also affects the vehicle's ability to accelerate, especially on wet or icy surfaces, or mud, with low friction coefficient [75; 76].