When you have 15k oil and have to go to bed, you put your squads on a eta 24 attack, with max delay. So you pay like 5k oil for example, and your oil is down to 10k. So you will add 5k more that night, but when you turn back your squads in the morning, you will get back the 5k that you paid earlier. So you have saved 5k more oil. Thats oil banking, a very essential activity before war for most non boosters.

Hmm... i'm going to start using that

Anyways, pertaining to this, I have done some thinking and realized that there really is no need for a god or afterlife. This life is perfect, just so long as you have no regrets when your time comes.