I don’t have a way of measuring lumens, although I checked the tailcap current of my OTR U18 (warm-white version):

Moon: 0.017A
Low: 0.30A
Med: 0.70A
High: 2.02A
Turbo: 2.62A (with freshly charged VTC5A)

(the visual observed difference between High and Turbo is not that significant…)