The regulations for the 1934 Grand Prix season brought larger bodywork requirements, so to counteract this, the engine was bored out to 2.9 litres.
Louis Chiron won the French Grand Prix at Montlhery, whilst the German Silver Arrows dominated the other four rounds of the European Championship.
By the 1935 Grand Prix season the P3 was hopelessly uncompetitive against the superior German cars in 6 rounds of the European Championship, but that didn't stop one final, legendary works victory.
The P3 was bored out to 3.2 litres for Nuvolari for the 1935 German Grand Prix at the Nürburgring, in the heartland of the Mercedes and Auto-Union empire.
In the race, Nuvolari punctured a tyre early on while leading, but after his next pitstop he carved back through the field until the last lap when Manfred von Brauchitsch, driving the more powerful Mercedes Benz W25, suffered a puncture, leaving Nuvolari to win the race in front of 300,000 stunned Germans.