It also has to do with the atomizer. If it's a tiny little thing with low air flow 4 wraps may work as a good balance of flavor vapor and heat up time at lower power... But bigger rebuildables have more air flow and need more vaporization of juice to blend with the air. Each wrap will produce vapor, there are other factors as too many wraps with too heavy a gauge of wire can cause a very slow vape. Bigger diameter coil will have less wraps than a smaller diameter coil of the same gauge and ohm. Building out for at least 6+ wraps works best in many cases.
