Minoura Mag500 trainer

I have a Minoura Mag500 trainer.
It has settings L 1 2 3 4 5.

which one should i use to be the most accurate ?

Bump! Sorry if this has been answered elsewhere but I haven’t found it. I’ve got the same trainer an have been experimenting w settings L, 1, 2 and 3 so far. Anyone have this benchmarked?