I'll take the confidence intervals if you've got 'em but, no, that's not really what I had in mind. I was hoping for something like:

1) "Studies have indicated that loose fitting closing decreases cycling efficiency by __% relative to tight fitting clothing" OR;

2) "My own tracking indicates that loose fitting clothing costs me ___ watts relative to tights fitting clothing."

This could take any number of forms that would help assuage my curiosity. I don't dispute that loose clothing increases wind drag and decreases efficiency. Rather, was hoping to understand the magnitude of the effect, relative to other factors, so that I might be able to weigh what I give up in cycling efficiency relative to what I feel that I gain in comfort when I ride in loose clothing.