Running out of fuel is read as running low on energy, motivation or resources. Tradition takes it as a sign that something needs refilling before you can go on.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.