That analogy doesn't work. You're not trying to heat the entire inside of the clearo, just the coil.
A protank does not take less power to run than any other coil setup at the same resistance.
Nevertheless, a true 8 watts on almost any bottom coil clearo will burn it after a while. If you like to chain vape you can get away with 6.5 watts for almost any length of time, but even then you can still burn them.
The anology was to dispel the statement that "nothing can be made more efficient". The analogy isn't so far out though because a fair amount of heat builds up in the base, at which point they have a tendency to overheat if you keep hammering them. You could say they are less efficient when they are cold, and more efficient when they are warm and you'd be a bit closer to the truth. Why is it so hard to believe (and no I didn't believe it either, threw away the Kanger card, and made all the usual mistakes
What are the main problems you hear about all the time with these?
1) It worked OK for a while, then I got a dry hit and it tasted burnt
2) My coils only last a day, then it tastes burnt
3) I put a new head in but my juice goes dark and tastes bad after one tank
All the result of trying to run these at 8 watts for an extended period of time. Then people tell them to pull some wicks out and you get:
1) It gurgles and produces almost no vapour
2) It works fine when the tank is full, but as soon as it gets to half it starts flooding
3) It just leaks and floods
4) It floods overnight and just keeps flooding
When you point out what Kanger's own recommendations are, and that they should return to that as a starting point, someone else *ALWAYS* chimes in and says "Oh, but I run them 8 watts" or 9, or 10, or even 11. If they only take the occasional puff, I can see that working. Chain vape on it and it's gonna burn though. Either that or their taste buds are permanently dead, or they've completely changed the head and it's resemblance to a factory made head is superficial only.
I get two weeks out of a coil with zero maintenance in that time. They are completely trouble and hassle free and all it needs is a wash and dry burn to get another 2 weeks out of it. Yes I might run it at 8 watts first thing in the morning when it is cold, but it's at 6.5 watts for the rest of the day and produces the same amount of flavour and vapour the whole day, and I can vape it down to almost the last drop. I will chain vape a couple of times a day, sometimes just to see the room fog up, sometimes because I really do need the nicotine, and sometimes because I'm in front of the TV or reading book and just zoning out.
I like fiddling and I've rebuilt these heads backwards and forwards. I've put coils made of cotton in them, I've pulled wicks out and I've put wicks in. I've tried high resistance, low resistance, and contact coils. The fact is though, the factory coil at 6.5 watts is all most people are really going to need because it just works.