The speed does affect the maximum range, but since it can do 20 nautical miles at top speed, that’s not so much a concern.
From wikipedia:
Is that right? 75 knots? Impressive.
The reasons I could see for having the torpedo run at a reduced speed would be increased effectiveness of acoustic sensors, greater manueverability (I’m guessing, I’m not familiar enough with hydrodynamics to know for sure), and increased stealth.
Cant confirm any of the operating characteristics of course but they are very quick! Yes, the lower speed is in fact used for certain search modes as I mentioned earlier. As much as everyone here wants it to be, it is NOT for “sneaking” up on the target. The torpedos have been getting quieter through advances in engineering.