Well, I'm using 15 ml a day. Came from 24mg, 18mg, 12mg, 6mg and now stationary at 3mg nicotine. My daily go to tank is an OBS Engine Nano that I use with Clapton coils at 40watts.
When I need to go ninja I turn up the heat to 60 watts and if I want the ISS to spot me from space I will buy me a mod that easily goes to 200 watts.
For now it's all about the nico :)
15ml would be a max for me, that doesn't happen often.
200w! At 40w these eats the liquid!