the awning tube is just under 16'. and now that I've had a chance to use it, I think I may back off to 3 turns each (pre-loading the springs).
I helped a friend replace the fabric on his carefree (70's model) and we tried several different numbers before realizing that it needed to be installed with no tension (when in closed position/up against the camper). it tensioned as we pulled it out, and retracted fine? tried that on this EZ-Awn first but it needed help gettting back to the closed position with a nice tight roll.