Some facts against the thesis of armchair historians without scientific sources or at least war memories of leading german persons:
German Fuel production 1939-1944:
1939: 8,2 million tons (synthetic fuel: 2,2 million tons, 27%)
1940: 7,6 million tons ( synthetic fuel: 3,348 million tons, 44%)
1941: 10 million tons (synthetic fuel: 4,116 million tons, 41%)
1942: 9,5 million tons (synthetic fuel: 4,920 million tons, 52%)
1943: 11,3 million tons (synthetic fuel: 5,748 million tons, 51 %)
1944: 6,83 million ton (synthetic fuel: 3,83 million tons, 56% )
Sources:
Dietrich Eichholtz:
Geschichte der Deutschen Kriegswirtschaft. Akademie-Verlag, Berlin 1985, Band 2, S. 354.
https://de.wikipedia.org/wiki/Deutsc...tisches_Benzin
In 1943 there were twelve producing hydrogenation plants. The hydrogenation plants covered most of the fuel needs of the Wehrmacht and were the sole source of jet fuel for the Luftwaffe.
https://de.wikipedia.org/wiki/Deutsc...tisches_Benzin
So the Wehrmacht could have fight at the eastern front a flexible defense strategy in 1943.
Different opinion is baseless talk.