In real life, you can get up hills in heavy trucks by only using the clutch biting point to power you forward. It is very hard or impossible in this game due to the biting point being in such a short area. Or due to lack of torque in the lower revs. Also the clutch biting point is always so early in every vehicle, which also is unrealistic.
You can do this in BeamNG, but the pedal travel on a sim wheel is much lower than that of a real car, making it much more difficult as the input is more sensitive.
Then you drive a car that has less travel and bunny hop the thing (in my grandads Mercedes Sprinter, just moving it around the land)