No use arguing with you, I guess I can try one more time.
If you can turn oil into fuel and into steam into eu into oil, it's not a dupe.
If you can turn oil into fuel and into steam into eu into MORE oil, it's a dupe.
You could be gaining .000000000001% more oil, it's still a dupe (at that point, nobody cares). But gaining almost half your input? It's most definitely a dupe.
If you can turn oil into fuel and into steam into eu into oil, it's not a dupe.
If you can turn oil into fuel and into steam into eu into MORE oil, it's a dupe.
You could be gaining .000000000001% more oil, it's still a dupe (at that point, nobody cares). But gaining almost half your input? It's most definitely a dupe.