The exact speed of a supersonic engine depends on factors such as the type of engine, the design of the vehicle or aircraft, and the altitude at which it is operating. For commercial passenger aircrafts equipped with supersonic engines, such as the Concorde, the cruising speed was typically around Mach 2, which is twice the speed of sound, making it about 1,534 miles per hour (2,469 kilometers per hour). Other supersonic aircrafts designed for military purposes can reach mach numbers ranging from 2 to 5 or even higher, resulting in significantly greater speeds in miles per hour.