BarnOwlLover
Staff Sergeant
The Allison P-51s weren't good for high altitude use, and (IMO sadly) there was only one Allison engine Mustang ace, and he flew the A-36 fighter/dive bomber variant interestingly. That said, the Mustang I and II was one of the few fighters equal to or superior to the Fw 190 at low/medium altitude until the Spitfire IX/VIII in 1942, and the RAF loved them for tactical fighter/recon roles. In fact, the RAF wanted more Allison P-51s for that role--but by then, production had switched to the Merlin models.