In 1940 Carrozzeria Touring Superleggera built three roadsters for the upcoming Mille Miglia known as the “Torpedino tipo Brescia”. These were built on the most developed version of the 6C 2500 known as the Tipo 256. Alfa Romeo switched focus from the 8C to the unsupercharged 6C in accordance with the 1939 ‘Sport Nazionale’ class.

Shape for the Torpedino came from a sole car built for Righetti for the Targa Abruzzo in August 1939. The three Mille Miglia cars were slightly different in detail, but had the same overall shape as the car which debuted at the Targa Abruzzo.

The three cars built for the 1940 Mille Miglia were raced alongside two Auto Avio Costruzioni 815s which had almost identical bodies from Touring Superleggera. That year BMW stunned the world by winning the ‘African Mille Miglia’ along a 1500km stretch of the Via Balbia between Tobruk and Tripoli. The Alfa Romeo of Giuseppe Farina and Paride Mambelli was 16 minutes off pace but placed second behind the much smaller engined BMW 328.

By 1939 Bruno Trevisan had to drop the supercharged 8C 2900 engines in favor of the smaller 6C 2300 enlarged to 2443 cc or 149.1 in³. To remain competitive they were upgraded to the Tipo 256 specification with help from Enzo Ferrari. Somewhere around 120 bhp was possible at 4750 rpm and this larger 2.5, 6-cylinder engine was offered on production cars beginning in late 1939 called the 6C 2500 Sport.

Of the three cars that were built, chassis 915091, 915092 and 915093, none survived intact. Due to their enticing shape, many replicas have been made which are incorrect in detail.