Minoia's career began in earnest in 1907 when he won the Coppa Florio driving an Isotta Fraschini, covering 485.7 kilometres in 4 hours 39 minutes and claiming the 50,000 Lira prize at the Corse di Brescia. This early victory established him as a serious competitor at a time when motor racing in Italy was still dominated by heroic long-distance road contests.
One of the most historically significant moments of Minoia's career came at the 1923 Italian Grand Prix at Monza, where he drove the Benz RH Tropfenwagen — widely recognised as the world's first mid-engine Grand Prix car. Derived from the visionary Rumpler Tropfenwagen design, the car placed its 1,991 cc six-cylinder twin-cam engine behind the driver in a teardrop-shaped body, and featured swing-axle independent rear suspension along with inboard brakes. Still naturally aspirated and producing only 65 bhp, it could not match the supercharged Fiats of the day, and Minoia finished fourth, but his participation represented a pivotal moment in the technical evolution of the racing car.
At the 1922 Targa Florio, Minoia drove for the seven-car Mercedes team that won the event, though his own car did not finish. In 1924, at the same race, he drove a 4.9-litre Steyr but retired after three laps when his riding mechanic became exhausted. That year he also finished fourth at the Italian Grand Prix in an Alfa Romeo P2.
At Le Mans, Minoia competed in both 1925 and 1926 driving Officine Meccaniche (O.M.) Tipo 665 Superba machinery. He finished 25th in 1925 with Vincenzo Coffani and fourth in 1926 alongside Giulio Foresti, a result that demonstrated O.M.'s growing competitiveness in endurance racing. At the 1926 German Grand Prix at Avus he set the fastest lap at 161 km/h in his O.M. before failing to finish, and at the Grand Prix of Europe at Circuito Lasarte he placed fifth in a Bugatti 39A.
Minoia's most celebrated victory came at the inaugural Mille Miglia in 1927, the first running of the legendary open-road race from Brescia to Rome and back. Driving an O.M. 123 with co-driver Giuseppe Morandi, he averaged 48.27 mph (77.68 km/h) over 21 hours, 4 minutes, and 48 seconds to claim victory. The win was a triumph for the Italian O.M. marque on home soil, and it gave Minoia a permanent place in the history of one of motorsport's greatest races.
In 1931, the AIACR introduced a European Championship for drivers, contested across three ten-hour Grands Prix — the Italian, French, and Belgian. Minoia, driving for Alfa Romeo, accumulated sufficient points to be crowned champion without winning any individual race. He shared second place in the Italian Grand Prix and shared sixth in the French Grand Prix in an Alfa Romeo 8C-2300, then finished joint third in the Belgian Grand Prix having switched to the Alfa Romeo 6C-1750. The championship was decided on aggregate points, and he narrowly beat Alfa Romeo teammate Giuseppe Campari, who had jointly won the Italian Grand Prix with Tazio Nuvolari. Minoia became the first-ever holder of the European Championship title.
He also competed at the 1932 24 Hours of Le Mans alongside Carlo Canavesi in a supercharged 2.3-litre Alfa Romeo 8C 2300, but the car failed to finish.
Minoia's career represented a rare continuity across distinct eras of motor racing — from pre-war Edwardian contests to the Silver Arrows era — and touched some of the sport's most historically charged moments. His victory in the inaugural Mille Miglia, his drive in the Tropfenwagen, and his European Championship title between them span the full arc of Italian and European Grand Prix culture in its formative decades.