1923 Grand Prix season

The 1923 Grand Prix season was part of a watershed year for motor racing that saw significant advances in motor-racing engineering, design and events. Fiat's chief designer, Guido Fornaca, developed the 805, the first supercharged car to win a Grand Prix. Benz appeared with the first mid-engined racer and, along with Bugatti and Voisin, produced some of the first efforts at aerodynamics on racing cars. With the United States also adopting the 2-litre formula, Harry Miller could use the smaller engine size to design the first single-seater race-car, ideally suited to American oval racing.

The inaugural Spanish Grand Prix for racing cars was held at a newly built oval at Sitges, near Barcelona. The first 24 Hours of Le Mans was held in June. The iconic race would influence the separation between grand prix and sports car racing and become a test-bed for production car development. The Belgian Automobile Club would promptly copy the format for its own 24-hour event at the new circuit at Spa-Francorchamps.

Alfa Romeo got a 1-2 result at the Targa Florio with Ugo Sivocci winning after Antonio Ascari's car stuttered almost within sight of the finish line. In the 500-mile race at Indianapolis, the new 2-litre Millers made up nearly half the field. Bugatti and Mercedes arrived from Europe, the latter being the first supercharged cars to race in the event. However, in a dominant display Howdy Wilcox and then Tommy Milton led most of the way in their HCS-Millers. Milton went on to become the first two-time winner of the event.

A strong line-up arrived for this year's French Grand Prix with most of the new models represented. Though extremely fast, the Fiats suffered on the stony roads of the Tours course and the superchargers ingested too much dust, wrecking the engines. This left Sunbeam, with a design closely resembling the previous year's Fiat, to take the victory. Henry Segrave became the first Briton, and Sunbeam the first British manufacturer, to win a Grand Prix.

The Italian Grand Prix at Autodromo Nazionale Monza was preceded by tragedy. Enrico Giaccone and Ugo Sivocci were both killed in separate practice accidents. Alfa Romeo withdrew its team. Fiat had fitted a new supercharger to their cars and on the paved Monza track would be unbeatable. Many of the teams thought that and therefore stayed away, however Benz and Miller did arrive. In the race Bordino set the early pace despite driving with a broken arm until he had to retire from exhaustion. Salamano took over the lead and held on to take a comfortable victory from teammate Nazzaro with Jimmy Murphy's Miller in third.

In voiturette racing, the undefeated Talbot 56 of 1922 was replaced by the Talbot 70 which was just as dominant. The Sunbeam-Talbot team drivers won every event they entered: Segrave won the first race at Boulogne, while Albert Divo won the Coupe des Voiturettes in France and at Penya Rhin. To close the year off, Dario Resta won at Sitges.^[1] The veteran Alessandro Cagno, winner of the first Targa Florio in 1906, won the Gran Premio della Vetturette at Monza in his last victory in a career spanning the history of motor-racing to date.^[2]