The gas issue was more of problem for the Axis with the few P-38’s they captured.
I get from the article that the P-38 was inferior at low altitudes compared to it’s German adversaries.
Yet we don't hear complaints about its performance in North Africa when it was encountering arguably better German pilots than it would face in the latter years of the war.
Comparing p-38 maintenance and performance reports across theaters would be an interesting topic for someone to research and write, or produce a documentary about.
I suspect it was some combination of fuel, air conditions, plane complexity, production and logistics that resulted in the p-38s flown over Continental Europe not performing as well as in other theaters.
For example, in the Pacific where I believe aviation fuel was all the same American blend and presumably matched what the Allison engines were designed for, how reliably did the p-38 perform in the Aleutians versus South Pacific? How did p-38 maintenance and performance in the cold, wet Aleutians compare with p-38 maintenance and performance in the cold wet conditions of northwestern Europe?
If Merlins were performing better over continental Europe than the Allisons, did anyone ever discuss taking a p-38 and replacing its Allisons with Merlins just to see what happened?
I also wonder to what extent egos were involved? Berlin was well within escort range of p-38s based in England but US Air Force doctrine going into the war was that heavy bombers didn't need fighter escorts.
By 1943, the 8th Air Force was being slapped in the face by the cold hard hand of reality. Bomber losses were high and no one planned production for large numbers of fighter escorts.
So, saying no long range fighter escort was available in 1943 was technically true but that was only because p-38 production did not factor in a need for large numbers of heavy bomber escorts.