ATM im set at 7watts DCT Pyrex with a 1.7ohm carto single hole and 70PG/30VG. I go up to about 8.5-9watts if i switch to a 1.5ohm dual coil. Pretty much anything in the 1.8-2.2ohm range i can get a decent vape around 7watts or 3.8v if its a single coil. As long as the juice wicks good it seems to work.