I also let my US friends talk on when they state the Mustang was an American plane.
the scotsman; jmacusa,
The Packard went into the P-51’s. The Rolls in the British planes.
Although the Mustang was designed for the Brits, it was thoroughly a USA design, with North American Aviation including a lot of cutting edge innovation. This is especially true regarding range and firepower, as well as ease of manufacture. Unfortunately, the P-51A’s all came with the Allison. It was not until the Brits jerry-rigged a Mustang with a Rolls Merlin, did the Mustang show what it could do. The Packard auto factory took the Rolls license and plans, made a few little changes for their manufacturing requirements, and ta-da, a legend was born.
Having talked to a number of WWII pilots who flew both fighters during the war and immediately thereafter, they were closely matched. Funny enough, there is a significant variation between airplanes of the exact specifications and model designations. In the end, it pretty much was a wash with personal preference being the biggest factor.
Oldplayer