I recommend starting with the 2.6 ~ 2.8 range and go from there. If you have manual batteries, remember that you can use the button to adjust somewhat. For more heat, preheat a little before starting your draw, and for less, release the button a little before finishing your draw. The ce2 I'm using at the moment tested at 2.7 ohm on my meter. I'm using it on a 3.7v e-power with 80/20 and getting good vapor. My draw is about 6 seconds.