The P-40's lack of a two-speed supercharger made it inferior to Luftwaffe fighters such as the Messerschmitt Bf 109 or the Focke-Wulf Fw 190 in high-altitude combat and it was rarely used in operations in Northwest Europe.
A falta dun compresor de dúas etapas no P-40 converteuno nun modelo inferior aos cazas da Luftwaffe como o Messerschmitt Bf 109 e o Focke-Wulf Fw 190 a gran altitude e raramente foi usado en operacións de combate en Europa occidental.