[Sailor Steve]

Originally Posted by Albrecht Von Hesse

The 44kts setting was used only by torpedo boats like the Schnellboote. (http://en.wikipedia.org/wiki/G7a_torpedo)

They don't give a source for that quote. Navweaps says nothing about it, and they quote several sources. On the other hand, they do say that the fast setting was troublesome early in the war as it caused the torpedo engine to overheat.
http://www.navweaps.com/Weapons/WTGER_WWII.htm