[req] Looking for authoritive info on surface endurance

[Ducimus]

Anyone know a site that has some authoritve information on exactly how far fleet submarines could travel? Or even a book and dont mind posting the specs listed?

Ive scoured the net repeatidly and sources all seem to vary, but generally agree upon the neighborhood of 12,000 NM @ 10 kts for most sub types, which i find hard to beleive when i find other sources that say for example one of the subtle differences between the tambor and gar was a bit more fuel. Some sources site one sub type of 96,000 gallons, another cites 100+ gallons, and the general slap of 12,000KM @ 10 kts is given, again, im skeptical.

By default the game has a 15,000 NM @ 10 kt endurance. Fuel management hardly comes into play. Unless thats a reflection of some wartme modification, id really love to bring it back down to historical specfications (whatever they are), and would love some more authorive info on it.