According to JJ Sadkovich, "The Italian Navy in WW2", out of some 786 ships over 500 tons (about 3.3 million GRT), some 212 (or some 1.2 million GRT) was outside the Mediterranean and thus lost. Including 46 tankers.
And the Italians had bugger all in the way of Tankers.
By way of comparison, in June, 1939, the British merchant fleet comprised 6,722 vessels of 17,891,000 grt. The Norwegians, for ghu's sake, had 230+ *Tankers* alone. And almost all went to the Allies.
The Regia Marina had a *minimum* requirement of 20,000 tons of oil *per week* just to keep the boilers ticking over, evidently (and fell below this in 1943), and which kept the escorts needed for the Libyan convoys mobile ... all of which was sourced from Germany (the Kriegsmarine was forced by Hitler to dip into *its* limited stockpiles to provide the fuel).
20,000 tons per week = 1,040,000 tons per year.
Just for the Regia Marina.
And you reckon they could have moved 400,000 tons of oil from nonexistent wells, for which they had neither the technology to drill as the oil was too deep for pre-1950's (and late 1950's) tech, nor the money and industry to develop said technology, run on nonexistent rail lines or pipelines, to nonexistent or patently inadequate port facilities and then back to Italy.
Right, pull the other one, it plays "Jingle Bells"
The fact that, as I mentioned, the Italians had to resort to shipping POL to Libya in 44 gallon drums in regular merchant ships, grossly inefficient at that was, or in 44 gallon drums *flown* across in German transport aircraft may be something of a clew that all was not well.
The Italians had neither the wells, nor the technology to drill them, nor the infrastucture to move any oil from them to ports, nor the port capacity to load their virtually nonexistent tanker fleet which, even if the oil had been available, couldn't have moved enough anyway.
I think that says it all.
Author, Space Opera (FGU); RBB #1 (FASA); Road to Armageddon; Farm, Forge and Steam; Orbis Mundi; Displaced (PGD)