## 3 Materials and Methods
### Measurements with Hatchback  
As mentioned above, the measurements with the hatchback were focused on determining the change in the axle loads and in the height of the center of gravity due to different load distribution. The weight applied to the front and rear axle was determined by newly proposed methodology via a pallet truck with a weight scale KPZ 52E-7/1, Figure 1. The deviation of weighing with the pallet truck is 0.5 kg [67]. The weight scale of the pallet truck (Position 1, Figure 1) carried two beams cross wisely (Position 2). The Euro pallets were located on the beams (Position 3). The principle of how the axle loads were determined by the weight scale pallet truck together with pallets is shown in Figure 2. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Vehicle**} & **Kia Ceed, 1.6** & \multirow{2}{*}{**Kia Sportage**} & **BMW i3s** & **Kia Sportage** & **Volkswagen** \\  & **CVVT** & & **(SUV)** & **(Electric)** & **Plug-in** & **Transporter** \\  & **(Hatchback)** & & & **(Hybrid)** & **(VAN)** \\ \hline Engine & 1.6 CVVT & 1.7 CRDI, & Electric motor & 1.6 GDi & 1.9 TDI \\ Engine power, & 93 kW, & 85 kW, & 75 kW & 44 kW, ignition & 62 kW, compression \\ engine type & spark-ignition & & & Synchronous & + electric & ignition \\ Outside size, & 4235/1790/ & 4440/1855/ & 4011/1775/ & 4515/1865/ & 4890/1904/ \\ body size & 1480 & 1635 & 1598 & 1650 & 1990 \\ (1/w/h) (mm) & 2650 & 2640 & 2574 & 2685 & 3013 \\ Wheelbase & 1710 & 1940 & 1730 & 2415 & 2600 \\ Kerb mass (kg) & 1263 & 1390 & 1365 & 1922 & 1800 \\ Wheelbase (kg) & 447 & 550 & 365 & 493 & 800 \\ Roof load (kg) & 80 & 100 & 75 & 80 & 80 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Technical parameters of vehicles [65; 66]. Figure 1: Pallet truck with pallets used for measuring the axle load. The vehicle (Position 4, Figure 2) was placed on the Euro pallets (Number 3) under which the beams were located (Number 2). Since it is a Euro pallet, its size is 800 mm \(\times\) 1200 mm. The wheel centers are located as much as possible in the middle of the Euro pallet transversely, i.e., about 400 mm from the longer edge, in order to prevent deviations from occurring due to pallet bending on the beams. The weight scale truck was located under the front axle (Position 1). The front axle was lifted by the pallet truck and water level to the same height as the rear axle in order to maintain the same height between the top of the pallets. Then, the weight applied to the front axle, including the beams and pallets, was subtracted. The net weight applied to the front axle was determined by subtraction of the beams' weight with the pallets. Such a procedure was further applied to the rear axle. To determine the center of gravity's height, it was necessary to determine the change in the weight applied to the front axle when lifted as well. The measurement with the lifted front axle of the hatchback is displayed in Figure 3.  
The front axle was lifted higher by the euro pallets than the rear one (Figure 3, Position 3) and also by using the maximum lift of the pallet truck (Position 1). The height of the lifted front axle was determined as a difference between the distance of the front wheel and the distance of the rear wheel from the axle. The front axle was lifted by about 520 mm higher compared to the rear axle. This value was determined by observing and measuring. At a lower value, there was no sufficient difference in the weights when weighing horizontally and with a lifted rear axle. When the front axle was lifted by more than  
Figure 3: Principle of determining the axle load via the weight scale pallet truck in the vertical direction. Figure 2: Principle of determining the axle load via the weight scale pallet truck in the horizontal direction. 630 mm, it led to a greater pressing of the rear suspension and rear wheel tires than when weighing horizontally, which has a negative impact on measurement accuracy and more corrections, or fixation of suspension's position, would be needed.