I am trying to figure out what the headlight sensitivity ratings mean. They go from1-4, but sensitive to what? More light or less light.

 

1 makes the lights turn on very early (even when going under an overpass) and 4 makes the auto lights turn on when the light is much darker.

I find that 4 still has the auto lights coming on before the street lights in my area.

 

I don't have 1 to 4, Is Lowest to Highest the same?

 

Thanks,
That's what I wanted to know.