Our technology also continued to evolve throughout the war, updated fighters, better engines, even whole new designs. The Germans as far as mass produced design

Our technology also continued to evolve throughout the war, updated fighters, better engines, even whole new designs. The Germans as far as mass produced designs went were effectively frozen in 1939. Well, not completely. "Greg's Airplanes and Automobiles" has a nice video on, "Why was the BF109K faster than the P51D? MW 50!" So to try and compensate for only having lower octane fuel, German engineers in WWII went to water/methanol injection for emergency power. Things did go back and forth quite a bit. Granted, the BF109 was one of the most advanced late 1930's designs going up against 1940's allied wartime designs. But there were times when updates on older designs would outclass the other sides slightly older versions, and this happened repeatedly on both sides. Technological choices were often driven by ideology, and perception, much more than in the other dictatorship at the time "Yes, but can it dive bomb?" probably did about as much to compromise designs of Nazi fighter/interceptors and slow the release of new airplanes as espionage and sabotage by the allies!