Why did Synthetic OIL not solve the AXIS OIL Crisis

The Axis suffered a colossal oil crisis in World War II. And today, we have two questions about this Kevin Dragos asked How did coalderived synthetic fuel affect Germany s overall fuel situation, and why could it apparently not sufficiently make up for the deficit of oil Craig Walenta asked At what point would German occupation of the Caucasus have materially impacted the Red Army s ability to fight the war