Cisitalia — the name derived from "Compagnia Industriale Sportiva Italia" — was founded in Turin in 1946 by Piero Dusio, an industrialist and sportsman who envisioned a racing enterprise built on accessible, cost-effective machinery. The D46 was conceived as a racing car that could be produced and sold to private entrants at a manageable price, while competing at the highest levels of the European voiturette scene.
The design brief was assigned to Dante Giacosa, who was ideally suited to the task. Giacosa had extensive knowledge of Fiat's parts bin, having previously designed the Fiat 500 Topolino before the Second World War. His approach was pragmatic: take proven, reliable Fiat components for the engine and suspension, then substantially modify them for racing use.
The D46's powertrain originated in Fiat street car components, but was substantially reworked for competition. The engine received dry sump lubrication, which allowed lower mounting in the chassis for a reduced centre of gravity, along with further modifications that raised output to between 60 and 70 brake horsepower from a relatively modest displacement. This was a significant increase over the standard road specification.
The chassis was a spaceframe construction — lightweight steel tubes forming a three-dimensional structure — and the completed car weighed under 400 kg (880 lb). This combination of lightness and adequate power gave the D46 a competitive power-to-weight ratio that allowed it to outpace more technically sophisticated but heavier and older racing machines.
The D46 made a successful competition debut in 1946, dominating the voiturette racing series in Italy. A pool of talented drivers took the wheel, the most celebrated of whom was Tazio Nuvolari, the legendary Italian driver then in the closing years of his career. Nuvolari drove the D46 to several victories, a remarkable achievement given that he was competing against machines from established manufacturers with far greater resources and experience.
The car's success was built on its combination of low weight, reliability, and exploitable handling rather than outright engine power. Where older racing cars from the pre-war era retained heavier construction and wore their years in weight and mechanical complexity, the D46 offered a nimbler, more modern package.
The D46's dominance in 1946 persuaded Dusio that Cisitalia could step up to the Grand Prix arena. He commissioned Ferry Porsche — son of Ferdinand Porsche — to design a full Grand Prix car, which became the Cisitalia 360. This was a highly ambitious, technically advanced machine featuring a mid-mounted engine and four-wheel drive. However, the 360 proved too expensive and complex to build, driving Cisitalia to the brink of financial ruin before a single chassis could be completed in competitive form.
In parallel with the D46's racing success, Cisitalia simultaneously pursued a road car programme with striking coachwork by Pinin Farina. The Cisitalia 202 GT of 1947, built on a chassis influenced by the racing department's work, was so acclaimed that the Museum of Modern Art in New York eventually acquired one for its permanent collection.
The Tipo D46 was followed by the D47 and D48 Monoposto variants, each representing development iterations on the original concept. Piero Dusio also attempted to use the D46 in Formula One competition: he qualified for the 1952 Italian Grand Prix at Monza, demonstrating the car's longevity as a competitive proposition several years after its initial introduction.
The Cisitalia Tipo D46 is recognised as one of the significant racing cars of the immediate postwar period. It demonstrated that competitive racing machinery could be built from repurposed production components if the designer possessed the expertise to identify and develop the correct elements. The car directly launched Cisitalia's brief but remarkable career as both a racing constructor and a coachbuilder of international renown. Its victories with Nuvolari at the wheel in 1946 gave the marque an instant pedigree that Dusio then attempted — with mixed financial results — to build upon at the highest level of the sport.