What do Zephyrus coils need such low wattage?

I have been using a TFV4 for the past six months or so and love it with the .15 tri-coils. Unfortunately it has a thread stripped somewhere so that its hard to get together after replacing the coil and leaks a little. I bought a Zephyrus V2 to replace it and I really want to like this tank. The black looks great on my mod and the capacity is just right. I bought a pack of .2 ohm coils and immediately burnt one up vaping at 85 watts, which was what I always did on the TFV4. I looked it up and see, not from an official source, but different vape stores are saying these coils are rated for 20-50 watts, which seems incredibly low for a .2 ohm coil. Am I wrong or is there something special with these coils. I turned it down to 50 and get a very weak vapor hit.