As you can see, your times are a bit off from what could be considered realistic. I'm not sure if this is intentional.

https://www.desmos.com/calculator/komxf4fvzw

Here's a little model of the underwater propulsion system.
Source:
https://uboatarchive.net/Manual/Manual.htm
+ original work:
https://github.com/mygamingaccount/u-boat-xcos

Can you make the spreadsheets in English? I get it in terms of historical accurateness, but the large majority of players speak English, and since this is just a workshop item and not in game, it would be much more easy to tell what's going on if it was in English!

Would it be possible to have different speed and values for the Typ VII B and Typ VII C?

Oh, and it's "Kleine Fahrt" not "Kleiner Fahrt"

Thanks for the work you're doing.
I'm not sure though I can agree with all of your values. I like the loading times in general.

However, the Typ VII C (which had about 10nm shorter underwater range than the VII B and was a little slower) could do about 80nm at 4 knots. So maybe it would be a good idea to designate "Halbe Fahrt" as 4 kts if possible.
To cover a distance 80nm at 4 kts would take 20 hours if my maths doesn't let me down. So the endurance of 11h in your mod will only let me cover 48 miles at 4.4 kts. That's 40% less range for 10% more speed.
My reasearch also said that a Typ VII could still cover about 8-10 nautical miles when running at AK. Which would give it an endurance of about an hour and not 35 minutes. So in that regard currently your mod doesn't seem to make it more realistic, but only more difficult.

I like the idea of slower - more loading :)
I have not played in a long while, and I do not remember the in game times.
So this seems to have longer loading times, and less time running on batteries.

Not easy ore not possible?
aint making any recuest here ,just curious?.

hmm interesting

@Ctbb. As I understand, the boat has only one diesel engine realized, so such modification will not be easy

@R6ckStar This mod must work without requiring a new career start

Wow this is long awaited at least by me thank you very mutch sir for making this modification
Btw do you think it is possible to make a mod that uses only one disel at the time?

i'm guessing not save game compatible?