Calculate how external accessories affect your real range.
Select the elements mounted on the roof. You can combine several.
Tow ball bike rack or light trailer.
Aerodynamic Drag: Drag force grows with the square of the speed. That's why a roof box is barely noticeable at 80 km/h but can cost an extra 20%% range at 130 km/h.
Weight Penalty: Every extra 100 kg increases consumption by approximately 3-5%% due to higher inertia and rolling resistance. This effect is more linear and less dependent on speed.
