During 1954, from the experience acquired with the 250S, started an escalation which finished with the birth of the 300S which was ready to be brought up in March 1955.
Because of ing.Colombo had gone to Ferrari, at Maserati, was adopted ing Ballantani’s theory of long stroke engine: 84 x 90 mm, with 2990 cc displacement. It’s power was quite the same of the 250F, but with a lower compression ratio, so it resulted that this engine was similar to the 250S’s one, with 6 straigth cilynders, DOCH, twin ignition.
Also the chassis felt the effects of the same constructive politcs which was used with the single-seater: some characteristic measures, the distribution of weights, the De Dion tube, the rear gear-box, were taken again. It had to substain a higher weight so it was formed by a trellis work with eliptic and circular tubes. The first chassis were built at Maserati, but the other were order at Gilco. Following the canons of the sportcars, the body was builted by Fantuzzi, a little massive but very pleasant. The big front intake was adorned with the traditional trident; the drive-seat was protected with a little breakwind which linked itself ideally with the embroidered head-rest, not always present. the sides of the car had a slit formed with some lamellas, in order to give outlet to the hot air of the engine room.
The left side, in particoular, was covered by two exshaust pipes which finishe near the rear wheel. The big rear, contained an enormous fuel-tank with 150 liters, the smaller oil-tank with 20 liters, and the provision wheel. There was even the door, very very small, to satisfy regulation needs.
The body, thanks to the experience and new aerodynamics theories, had a certain functional and stylistic evolution which started from the n°3063 due to Bordoni during march 1956: the snout was extend a lot. In 1957 the entire body was modified and it was very similar to the 200 Si.
The disaster of the 1956 at Sebring forced Fantuzzi to open to intakes on the snout to give refreshement to the front brakes, forced to substain monstuous temperatures. In the rear part already in 1955 for the Sicily race, to solve the same problems, were opened two little intakes on the mudguards.
From tne n°3057 were adopted the carburettors by Weber: thy were the 45 DCO3, then only one exshaust pipe, and Alfieri tryed but without any result to introduce the enjection system. Afer the 1957 Mille MIglia, were often used the brakes of the 450S. During all it life, the 300S had 4 gears with an exception: 5 gears which were installed in the n°3080.
The 300S was a very important car in Maserati’s adventures: for two years was its best car, in 1956 it was very near to win the championship, and gave to the factory great commercial and sports success. In 1957 with the birth of the 450S, its succes got lower, but however it had also many qualities to demonstrate, and in several occasions it made up 450S’s weakness.
Unfortunately, in Europe from 1957, because of the terrible accident of Guidizzolo during the Mille Miglia, started an hysteric campaign against the sport car races, so italian cars, emigrated to USA, where these races were still in a rising phase. Among these, there were also the last 300S, builted with unproductive materials to face the economical chrisis of the moment. Maybe this reasons can explain why the numbers 3082 and 3083, don’t exist in the documents of the factory although their existance seems to be demonstrated by their survival at pprivate collectors.
During 1958, considering the limitation of displacement to 3 litres, Maserati builted a promotional 300S with a V12 engine, which was builted in three versions: 2874.5 cc (73.8x56 mm), 2980.9 cc (70.3x64 mm), 2980.9 cc (68.2x68 mm). The car equipped with the 350S’s chassis n°3503, was tested at Nurbrgring in june 1958 but there were too many problems to go on with the develop of the car, so the project was abandoned. In 1959, when there were again the presuppositions to race again, displacement was increased to 4 liters: it was the moment of the fantastic "tipo 61".