[Stealhead]

Not sure with stock in TMO and RFB your range gets better the slower you go and gets worse while you are charging batts then goes back to normal and ahead standard is the most efficient for regular patrolling from a fuel consumption/time to get to station/area coverage standpoint but if you are dangerously low slower would be better.The speed that each given sub goes at standard is different in each version due to differences in the goals of each mod as is the consumption rate RFB is the the most brutal and accurate TMOs simulates later war fuel ballast modifications that allowed higher speeds and is also accurate if you read the explanation in the PDF and stocks is well its stocks and is the hardest thanks to the guess work.

Because Stock has no nav officer giving this vital data I never took the time to try and figure it out myself so with stock standard might get you the best range I don't recall.In all versions charging batts consumes more fuel than surface running alone aside from the last few mile batteries cheat even with that it wont work at 1800nm and I'd bet that using it that far away he will run out for certain.