ujoint

Hi I'm new to this hole thing, just some questions. I just got a new set up here. X6 and the tank is a K ranger Tech Proton 11 mini, and wondering what's would be the best coil? I had a 1.8 in my last ecig and it was a ItastVV with a xjet tank. I tried a full wick style on the last one and never liked it much, so I've stuck with the clear cartomizer set up. So I don't really understand the hole coil voltage. I tried the 1.8 in the new set up (x6) and I just swapped out to a 2.0 and it seems to work little better. So what's the real difference between the could voltages? Thanks I hope y'all can make sense of this

Hi how's it going out there in the vape world