If it’s the VDO dipstick sender, they work just fine. If it’s one of those things you connect to the oil light, the light will be forever flashing at you.
The bug engine runs cooler around 90 degrees C so the sensor is set too low for a bus. In a bus where the engine oil goes up normally to 110+ degrees C, the light will be flickering 100% of the time, with nothing wrong, except the driver constantly being distracted, until their brain filters out the light on situation, so when it dumps the oil or sucks air they dont notice and wreck the engine anyway.