Additionally, many of the late-war engines also included a system for high-altitude boost, GM-1, which was intended to add oxygen to the fuel/air mix by injecting nitrous oxide into the supercharger instead of employing higher boost levels – the Jumo 213E inverted V12 on the Ta 152H could "sprint" with both boost systems engaged to airspeeds of well over 560 kmph at low altitudes.