The Alfetta, as was designated the small Alfa Romeo 158, was designed and build between 1936 and 1937, in the workshops of the Scuderia Ferrari, the official team of the Italian manufacturer at the time, in response to the dominance of the German teams, Mercedes-Benz and Auto Union, on the Grand Prix races of the 2nd half of the 30s.

 

With a budget far more limited than the rivals, Alfa Romeo, driven by an Enzo Ferrari suggestion, decided to invest in building a single setter to compete in the class designated as the "Voiturettes", of smaller engine capacity and whose races followed in part those of GP. The responsibility of the project was given to Gioacchino Colombo, who had worked with the renowned Vittorio Jano, designer of the Alfa P2 and P3, which gave the Italian team so many victories.

 

With a classical tubular chassis, the Alfetta was characterized by a low driving position, thanks to-center displacement of the shaft and to adopt an 8-cylinder engine in-line, of 1500 cc (hence originated the model designation: 1,5 Liter+8 cylinder=158), with two camshafts to head and using a Roots compressor. The initial power of 180 hp at 7,000 rpm, has come to increase up to 350 hp at 8,600 rpm, in the models lined up for the first GP of the modern era, in 1950, at the Silverstone circuit in England. The 4-speed gearbox, cross placed, was disposed along the rear axle. The independent suspensions were composed of transverse springs with longitudinal arms in the front and oscillating ones in the rear.

 

The premiere, on August 7, 1938, in the Ciano Cup, at the Italian circuit of Livorno, could not have gone better, with the victory Emilio Villoresi. In the remainder of season, as well as in the following year, the repeated victories confirm the little Alfa to be superior to the competition of Maserati and ERA. The exception to this technical supremacy happened in the GP of Tripoli of 1939, where Mercedes surprised everyone with the new W165, of the same class and built in secret and in record time for the new regulation, to the following year.

 

The last race before the forced interruption by the war, which raged through Europe, ended with a victory by the 158, in the GP of Tripoli of 1940, after which the cars were hidden in a cheese factory on the suburbs of Milan. In the post-war return of the races, the Alfetta again dominated the "Voiturettes" category, from 1946 and, in the following year, with the regulatory change of FIA, the 158 became part of the GP class. The deaths of Achille Varzi, driving an Alfa 158 and of Jean-Pierre Wimille, when driving a Simca-Gordini in 1948 and 1949, respectively, led the Italian manufacturer to the remoteness of the competitions, but when the World Championship of Drivers came up in 1950, Alfa Romeo decided to return and signed up with four cars.

 

The Alfa 158 was at the height of its development and won all the 11 races in which he participated, 6 of which counted for the newly created Championship. It was driven by the "3 F", Farina, Fangio and Fagioli and dominated the now opposing, Scuderia Ferrari and finished the championship in that order.

 

The Italian Nino Farina won the inaugural race, held in the British Silverstone circuit on May 13, sharing equitably the victories in the Championship with Argentina's Juan Manuel Fangio. For the last race, held on September 3, at the Italian circuit of Monza, which decided the champion, Alfa Romeo gave these two drivers the brand new 159 model, the 158’s natural evolution, designed to respond to the growing threat of Ferrari, revealed itself increasingly competitive. The victory crowned Nino Farina as the first World Champion of Formula 1.