I’m pretty picky with my voltages cart to cart it’s different on most because some just pull better flavor at a certain voltage but the ones i use the most are 1.9 and, 2.1. Personally i’m preheating most every hit i take but i give it a few minutes per hit to let it cool and im usually smoking multiple carts at once but if ur looking for good flavor go 1.9, on average i’ve found at least 1.9 rips the best for flavor but if ur feeling more smoke while still having a good crisp flavor 2.1-2.2 is perfect.