As Alfred Price has written, the speed of the V-1 varied a lot because it was built by slave labor, and not to aircraft tolerances. According to Price, the V-1 cruised at about 3,000-4,000 feet at speeds ranging from a low of 300 m.p.h. to a high of 420 m.p.h., with the average speed being 350 m.p.h. The high end of that speed range, at low altitude, would have been too much for most Allied fighters.