Introduced in 1925 and offered through 1931, the Phantom I was actually the replacement for the Silver Ghost, a model used before 1925 that had a smaller engine in comparison. Built in Derby, England as well as Springfield, Massachusetts, the Phantom I obtained minor differences based on if it was built in Britain or in the United States. Major differences included the wheelbases and transmissions. As for minor differences, the fuel gage placement differed, and the oil pressure gun. All mechanical parts were produced by Rolls-Royce, all fitted by designated coachbuilders. The first of its kind, it paved a way for future models to find similar success.