OK, first test results are in from this test:
http://www.subsim.com/radioroom/show...48&postcount=3
Boat:IXC with IX/2 conning tower, deck gun and MAN Turbocharger
For the periscope depth run and the battery charge after:
Weather: 5
Test Distance:155.9km
Max distance1: 14120km
Max distance2: 10936km
For the surface only run:
Weather:
6
Test Distance:
Test distance (115.9km)
Max distance3: 14488km
Max distance4: 13901km
Conclusion
Indecisive; further tests needed.
The submerged run used 3184kms worth of fuel in 155.9km. It is using almost 20.5kms worth of fuel to go 1km.
The surface run used 587kms worth of fuel to go 155.9km. It is using 3.7 kms worth of fuel to go 1km.
On the surface these number suggest that surface running is far more efficient, This is made even more dramatic when you account for the worse weather on the surface run. However, if the numbers where totally accurate then the surface run should have used 155.9kms worth of fuel to go 155.9km. i.e. 1kms worth of fuel to go 1km!
This difference could have been caused by:
1) Innacurate testing
2) Inaccurate NO maximum range prediction
3) The weather.
I will conduct the test twice more to get better results and reach a proper conclusion.