The European rounds of the championship were plagued by entry withdrawals of the works teams, leaving just a handful of starters to contest the races.
The most embarrassing was the premier French Grand Prix where only the three Bugatti works cars started, and Jules Goux won, being the only classified finisher.
Germany held its first Grand Prix, won by the young Rudolf Caracciola in difficult wet conditions that caused several serious accidents.
[41] In May, the cities of Milan and Turin changed their rules of driving on the left side of the road to line up with the rest of Italy that drove on the right.
[36] Faced with high development costs, Alfa Romeo and Sunbeam instead chose to retire their works teams from racing.
[51] Using the engine and chassis parts Alfieri had designed for the last Diatto racer, their first grand prix car was the Maserati Tipo 26, named for the current year.
The French were competing against a solid field of privateers, led by the local hero, and two-time winner, Conte Giulio Masetti racing another Delage, Emilio Materassi in his 5.8-litre Itala Special and Renato Balestrero in a works-supported OM.
At the end of the first lap, Costantini (the 1925 winner) led from Minoia, with Materassi, Wagner, Dubonnet, Divo, Goux and Maserati all about 3 minutes behind on elapsed time.
Last year's winner Peter DePaolo ran its new supercharged 1.5-litre model along with Ralph Mulford and Bob McDonogh while rookie Ben Jones had a 2-stroke special.
He had Ralph DePalma’s Miller from 1925 (renamed an Elcar Special) but crashed on his second qualifying lap when he clipped the inside wall at speed.
[62][60] After qualifying, Cooper had the fastest time, sharing the front row with Hartz and Duray's Fengler with a field of 28 cars.
[4] Pete Kreis was too ill with flu and handed his drive over to young rookie Frank Lockhart who had shown great speed qualifying as a relief driver.
The first European round of the World Championship was the French Grand Prix – this year held at the very fast Miramas oval in the south.
Goux won by sixteen laps as the sole classified finisher, but at least it gave the Bugatti team the handsome prize of FF100,000.
Another promising entry list of 21 was once again stymied by non-appearances, this time also including OM, Jean Gras and the privateers Albert Guyot and Ernest Eldridge.
Delage did arrive with their new cars and team drivers Robert Benoist, Edmond Bourlier and André Morel, with Louis Wagner as a reserve.
The Talbots were finally ready and driven by Henry Segrave, Jules Moriceau and joined by Albert Divo who had raced for Delage the previous year.
Just at the halfway point Segrave pitted to fix an ongoing engine issues when the car caught fire forcing his retirement.
For the final race - the Italian Grand Prix - the only two manufacturers eligible for the title were Bugatti and Delage, as no others had competed in at least two of the earlier rounds.
[74][75] In the 400 km voiturette race, run simultaneously, the winner was André Morel in the works Amilcar (being only four laps behind the Bugattis at the time).
Segrave won from his teammate Moriceau in their Talbot 700s, beating the Bugattis of William Grover-Williams and Louis Chiron.The second Marne GP was held on a new road course near Reims, a very fast triangular track of long straights joined by sharp hairpins.
The three regular Delage drivers had recovered from their earlier ordeal and faced the three unsupercharged Bugatti T35s of the works team, and two 2.3-litre Targa-spec privateers.
At the halfway point, the rain had eased and Costantini had a 6-minute lead over Wagner's remaining Delage, with Goux, privateer “Williams” and Minoia a lap behind.
Maintaining his fast pace, Costantini won with a 2-lap lead over Goux who finished second after Wagner, relieved by Benoist, had their issues.
[80] A national race for sports-cars the previous year on the Kaiserpreis circuit in the Taunus mountains had been won by August Momberger in a supercharged NSU 1.3-litre.
As well as works cars from OM, NSU, Brennabor and NAG, there were a raft of privateers and gentlemen-drivers, including Jean Chassagne and Hugo Urban-Emmerich running British Talbots.
They ran 1924 2-litre Grand Prix cars, modified to carry a second seat and unofficially assisted by Alfred Neubauer and his team.
[81] Several weeks before the race, Kurt Neugebauer had almost had a major accident when his NAG got into a slide at 150k/h on a wet AVUS track.
[86] Mercedes arrived as a works team at Solitude in September, running their 2-litre 1924 cars again, this time for Otto Merz and Christian Werner.
Although no works teams were officially entered, there were team-entries running the latest Talbot, Alvis, Aston Martin, Salmson and Amilcar models, along with the previously seen Halford and Eldridge specials.