1925 Grand Prix season

The 1925 Grand Prix season was the first year for the new AIACR World Manufacturers' Championship season. The championship was won by Alfa Romeo , with its P2 model.

In January, the AIACR had settled on the championship format – four Grands Prix to be held in the US, Belgium, France and Italy (of minimum 800km length), with compulsory attendance of the Italian GP and the manufacturer's home race to qualify. The best three of the four results would count. It ran on the successful 2-litre formula already in place.

This year, the Targa Florio was a competition between the French teams of Bugatti and Peugeot as the major Italian teams did not enter. In a close race, the Peugeots initially led but it was the smaller Bugatti of Bartolomeo Costantini that came through for the victory. Louis Wagner was second for Peugeot, after he was delayed when stopping to assist his teammate, Christian d'Auvergne, who had been seriously injured in an accident.

Only a small entry lined up for the Indianapolis 500 , dominated by Millers . Dave Lewis ran the new Miller – the first front-wheel drive car to enter the race. The Duesenberg challenge was led by the previous year's winner Peter DePaolo . From the start the Duesenberg teammates DePaolo and Phil Shafer set the pace. Just after halfway, DePaolo pitted suffering from blistered hands, taking relief from Norman Batten while the injury was attended to. Lewis in the FWD Miller got to the lead but was ...

The inaugural Belgian Grand Prix had only seven entrants with only the Alfa Romeo and Delage works teams starting. Then when all four of the French cars had retired by half distance, it left just Antonio Ascari and Giuseppe Campari circulating to give Alfa Romeo a 1–2 victory. The blue riband French Grand Prix did have a more complete entry list and was held on the recently completed full circuit at Montlhéry . Once again Ascari leaped into the lead until he misjudged a corner and crashed. Serio...

Sources: [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ]

Major non-championship races are in bold Sources: [ 6 ] [ 7 ] [ 3 ] [ 8 ]

Sources: [ 21 ] [ 22 ] [ 23 ] [ 24 ] [ 25 ] [ 26 ] [ 27 ]

Note: * was raced as a relief driver. Those in brackets show, although entered, the driver did not race

The AIACR (forerunner of the FIA ) 2-litre regulations for Grand Prix races remained unchanged. In the United States, the American Automobile Association (AAA) stayed with the same regulations as well. The AIACR followed the American example to remove the mandatory mechanic on board, replacing him with a compulsory rear-view mirror instead. [ 28 ] As the circuits used became shorter, as well as the danger to the passenger, the mechanic had become superfluous. [ 29 ] Incongruously, the cars still...

The Targa Florio regulations remained open to any sized cars. The smallest engine classes were merged up to 1.1-litres and only ran three laps. Each car had a minimum weight of 120kg and, unlike other regulations, had to have a driver and a mechanic (who was not permitted to drive). The crew was allowed to be swapped at the end of a lap with a pre-registered substitute crew. With a maximum time limit of 10 hours, each entry had to finish within an hour of the class winner to be classified. [ 31 ...

[ 33 ] [ 34 ] As early as the October 1923 meeting of the AIACR, there were discussions about holding an international championship. The initial ideas were for a European competition including grand prix, touring car and endurance events but there were concerns about achieving a balance of performance.

At the January 1925 meeting, the Automobile Club of Italy gave its proposal to the committee – for an ongoing international series through to 1930. The 1925 season would comprise the existing Grand Prix of Italy, France and Indianapolis as well as new Grand Prix for Spain, Belgium and Great Britain. The committee voted to omit the Spanish GP, and Brooklands had to cancel the British race because of legal action with neighbours about noise complaints. Each race had to be at least 800km long and r...

The championship was for manufacturers, not individual drivers, and to be eligible teams had to enter the Italian GP, as well their own national GP if available. They would only score points from their best three results of the four races. The winning manufacturer would receive FF70000 cash prize as well as a FF30000 bronze and gold trophy designed by Italian sculptor Antonio Maraini. [ 37 ]

Only the best-finishing car for each manufacturer would score points, which were awarded as follows:

And in the case of a tie, a 200km race-off would be held at Monza within 2 days of the Italian GP. At the February meeting the committee ratified the proposal. They also voted to exclude German teams from the Championship, as Germany was not a member of the AIACR, and they were still not permitted to officially race in France, Great Britain or Belgium.

Fiat and Rolland Pilain had retired from motor-racing. Alfa Romeo had dominated the previous year with their P2 model. Between seasons, chief engineer Vittorio Jano further developed the engine, boosting its output from 145 up to 155 bhp. With new fuel for the year, an additional forward fuel tank was fitted for the higher consumption, as were larger drum brakes. [ 39 ] [ 40 ]

Delage joined the other top manufacturers by supercharging their 2-litre V12 engine. They chose to use twin Roots-style superchargers. The power output was 190bhp, closing in on the “magical” 100bhp per litre milestone. However, despite a 5-speed gearbox, the chassis was still not capable of transferring all the power to the road. [ 39 ] The bonnet was now louvered to try and dissipate the great amount of heat generated by the engine. [ 41 ] With riding mechanics now banned, Sunbeam fitted their...

There were also several specials entered in Grand Prix. Albert Guyot had been a regular driver for Rolland-Pilain who had also raced at the Indianapolis race since before the war. He took three of the Rolland-Pilain cars, adding a Cozette supercharger to a new Burt-McCollum sleeve-valve engine . English driver Ernest Eldridge took an Amilcar GS and fitted a 1.5-litre supercharged Anzani side-valve engine that got up to 185 km/h. [ 43 ] [ 44 ]

After the 1924 Indianapolis race, Jimmy Murphy had suggested to Harry Miller that a lower centre-of-gravity would increase cornering speeds. That could be achieved with front-wheel drive obviating the need for a central driveshaft. Miller started work on it but, sadly Murphy was killed later in the year. The Miller FWD had a supercharger giving out 200 bhp. He also supplied supercharger kits to his customers that they could retrofit to their cars, which many did. [ 28 ] [ 45 ]

The Duesenberg had a vanes-type compressor, that could rev at up to 30000 rpm, far higher than the Roots supercharger. This format gave them better performance at low speeds. The wider wheelbase also gave greater cornering stability. [ 46 ]

This year the season opener was a new event, the Grand Prix of Rome, held in February. The race was run on a 10.6km circuit on the streets of Rome north of the Vatican City . A big field of 35 starters lined up for an overall prize of 100000 lire. Predominantly Italians, a number of top drivers entered including Conte Gastone Brilli-Peri in a Ballot designed for the 1919 Indianapolis race, Emilio Materassi with his pair of his modified Itala Specials and Conte Carlo Masetti in a Bugatti 35. He w...

The first event in Africa for grand prix cars had an inauspicious start. The boat bringing the small-engine cars from Italy mistakenly offloaded them in Benghazi , so their race was delayed by two days. This left a small field of five in the over 2-litre class in their own race on the Thursday. Then on Saturday the ten smaller cars had their race. Renato Balestrero , works driver for OM won from Luigi Platé , who drove his Chiribiri with his wife as the co-driver. [ 54 ]

The Bugatti team returned to Italy for the Targa Florio. Once again, the event was run in conjunction with the Coppa Florio, with that being based on the results of the event's first four laps of the newly sealed Madonie circuit. In 1924, the grandstands had been destroyed by a fire but within a year they had been rebuilt. [ 55 ] Whereas in 1924 the German teams arrived in force, this year it was the French. Bugatti had a three-car team with Bartolomeo Costantini and the Spanish de Vizcaya broth...

The field started at 4-minute intervals with the Peugeots, as the only entrants in the Coppa Florio, going out first. [ 56 ] They set the early pace with Boillot setting a new lap record on the first circuit (assisted by the better quality roads). Going into the third lap, now led by Wagner they were running 1-2-3 with Costantini three minutes behind. However, d'Auvergne missed a corner, hit a wall and rolled. His mechanic was thrown clear while d'Auvergne lay pinned under the burning car. Wagne...

The Grand Prix d’Ouverture heralded the official opening for racing at the completed Autodrome de Linas-Montlhéry outside of Paris. Held on the oval circuit, it was restricted to voiturettes up to 1.5-litres with 150000 francs in prizes. A big field was therefore expected but this waned when the works teams from Bugatti and Chiribiri withdrew. This left the Talbot team as the overwhelming favourites, with Henry Segrave , George Duller and Conte Caberto Conelli . They were joined by racing specia...

Table lists the highest race position for each manufacturer. [ 97 ] ** non-participation disqualified the manufacturer from the championship

* Only one dropped score allowed

italics show the driver of the race's fastest lap. Only those drivers with a best finish of 6th or better are shown. Sources: [ 98 ] [ 99 ] [ 100 ] [ 101 ] [ 102 ] [ 103 ] [ 104 ]