There's a lot of old significant other's tales and conventional wisdom/a.k.a. BS floating around on the subject of bicycle drivetrain efficiency. Here are some actual instrumented IGH and derailleur drivetrain efficiency tests by respected people in the cycling world:
(beginning on page three of)
HP52/2001
(in German, try google translate)
Fahrrad Zukunft no. 17
thanks tcs
interesting read..... interesting also that the rohloff was tested without a chain tensioner ... and being the german " wunderkind" tested by a german ... i tend to wonder .. just a little bit ...
also interesting and somewhat almost expected that the Nuvinci is better for weaker riders, than stronger riders ...