@trex5365, thanks for the detailed answer! It was interesting to read it. 
I am not a real-life pilot, but I think it is hazardous in real life if an engine stalls when the fuel indicator is not zero. I guess that is why my motorbike can work several decades of minutes at the instrument’s zero readings. I understand that I do not have any fuel for this reading, and I should do something as soon as possible.
The story that led to the writing of this post:
I got lost and made a short detour to the airfield, spent more fuel than I expected. Having found the airfield, I checked the fuel gauge readings, and I made sure that I had fuel for 30-45 minutes of flight (5-6%). I did not take any action to save fuel and las as soon as possible. On the contrary, I began to make a U-turn to enter the runway against the wind. Suddenly the engine stopped when I was far away from the airfield…
I would have acted entirely differently if I had seen zero on the fuel gauge. It would be more helpful “fortunately” the engine was running at zero readings than stalling at the moment when I was sure that I had at least 30 minutes of engine operation left.