Fuel is not running out!!
 

I started a carrer and I set the options for what I wanted for gameplay, everythign is pretty realistic except the external camera..
But then I still see the fuel at 100%..

I then saved the game and went back to the main menu and it puts everythign back to standard (easy?) I don't like that, so I set it back again..

I don't know whats going on, any help?
THANKS

The realism settings in the main menu don't affect the campaigns. To change the settings in a campaign you've started, you must be in the main office. For the US campaign the Options are found by clicking on the radio on the left side of the screen above the bookshelf. Here you can customize your realism settings.

When you begin a new career, it asks you for a chosen difficulty rating. This overwrites the realism settings you chose in options, which is why you have to follow Zantham's instructions to reset them where you want them. This will happen every time you start a new career in the future. Each difficulty rating has a different set of options: Hard usually checks every realism setting while Easy checks none, and the ones in the middle check some and not others. Further, some mods change these. Hard setting in Trigger Maru Overhauled, for example, leaves No Map Updates and Event Camera unchecked, but sets all the others to true, and counts as 100% realism.

Ummm.. Can't I decided what I want and don't want?
For example, I WANT TO RUN OUT OF A FUEL, but DO NOT want to target my torps.

Yes, you can

Sadly, that's not true. There is only one set of realism settings for all single missions and all the campaigns.

??? What do you mean by that? Changing the realism settings via the main menu certainly don't have any effect on any ongoing campaigns/careers, it has to be done from the office.