The lack of competitiveness of the 250S led Maserati to design a new engine with increased displacement from 2.5 to 2.8 liters. However, the engine did not give the desired results and it was thus that the designer Vittorio Bellentani designed a new 2992cc in-line 6-cylinder. The Sport on which the engine was mounted, the 300S, was completed in 1955 and proved to be very competitive, nearly winning the World Sport Championship in 1956. The 300S continued to run until 1966, fielded by privateers, in Italy, in the United States and in South America. The best known pilots who drove the 300S were Fangio, Moss, Behra, Musso, Shelby and Bryan. 27 units of 300S were built.