Since I've started using a tank with my VV mod, it's of course easier to pay attention to how much liquid is being consumed. Yesterday, I was feeling a bit dissatisfied with what I was vaping and, for the first time in quite a while, hooked up the multimeter to check my voltage. I was somewhere around 4.0V and decided to crank it up to 5V. Much better. But it seemed like I went through that tank much more quickly than before. Not just 20% faster as I might have expected, but seemingly closer to twice as fast. This was obviously not a controlled experiment and it's entirely possible that I was dragging more greedily, owing to my increased enjoyment. But it led to a question: is the relationship between voltage and vaporization linear, or does the curve get steeper with an increase in voltage?