German tanks were always running out of fuel. One big reason that the defeated Brits got away at Dunkirk was that the panzers were immobilized from both lack of fuel and also the fact that the tankers had been going on benzedrine for about a week with no sleep at all.

My recollection from Speer's memoirs is that oil production from coal peaked higher and later than you state, but Speer could have been wrong, or (Yes, it has happened a couple of times.) my memory could be in error.

Agreed.
The Germans were always chronically short of gas, made much worse after the loss of the Rumanian Oil fields.
In fact , perhaps The Second World War should really be  called 'The First Oil War'. Japan and Germany both
had the same problems. Anyway, thats history. I believe that South Africa has made the best shot at the
F-T Process during the years when they were under economic sanctions. But again, more I think from desperation than economics.
It HAS been called the first oil war, but I forget by whom.