The AIACR reinstated the European Championship, requiring each qualifying Grande Épreuve to cover a minimum of 500 km. The Swiss Grand Prix, successful in its inaugural 1934 running, was elevated to championship status, bringing the total to seven events. The voiturette formula was extended to 1.5 litres, attracting larger and more competitive fields. The Independent Drivers' Association was formed in Paris during the year, as the rising cost of competitive machinery progressively excluded sole privateers from the top-tier calendar.
Mercedes-Benz kept the W25 as its base and progressively bored out the engine from 3.7 to 4.0 and then 4.3 litres. Auto Union introduced the Type B, featuring torsion bar rear suspension and an enlarged engine of 4.9 litres, later 5.6 litres, producing over 375 bhp. Alfa Romeo overhauled the Tipo B with a 3.2-litre engine, new independent rear suspension, and hydraulic brakes, while Scuderia Ferrari also received the new interim 8C-35 late in the season — a 3.8-litre design with fully independent suspension. Enzo Ferrari unveiled the Bimotore for open-formula events: two 3.2-litre Tipo B engines mounted fore and aft of the driver, developing up to 540 bhp but savage on tyres and fuel. Maserati introduced the V8-RI with an independent four-wheel suspension layout, though the company's lack of investment left it underdeveloped.
Mercedes dominated the opening races. Luigi Fagioli won at Monaco after the Ferraris faltered, and Caracciola took victories at Tripoli and at the Belgian Grand Prix, where his teammate Fagioli provoked a furious argument with team manager Alfred Neubauer by refusing to defer to him and walking off. At the French Grand Prix, a chicane-laden Montlhéry circuit was intended to blunt German speed; instead all three Mercedes finished on the podium, with Caracciola taking the win from von Brauchitsch by half a second.
Bernd Rosemeyer made his debut with Auto Union and immediately impressed, running Caracciola to 1.2 seconds in terrible rain at the Eifelrennen before a late-race mechanical problem cost him a certain victory — only to have Caracciola squeeze past at the final corner.
The German Grand Prix at the Nürburgring delivered one of the defining races of the era. Nuvolari, driving a Scuderia Ferrari Alfa Romeo before a crowd of 250,000, found himself in sixth place after a poor pitstop and with both teammates already retired. Putting in fastest laps that astonished the crowd, he tracked down the leading von Brauchitsch, who had been signalled by Neubauer to ease off. On the final lap, von Brauchitsch's rear tyre failed on the long run to the grandstands, and Nuvolari swept past to win by a margin impossible to overturn. The stadium fell into stunned silence. Officials had no recording of the Italian national anthem, but Nuvolari always carried one with him. Doctors later found Caracciola had been competing while suffering the effects of a tapeworm.
After this high-water mark, Varzi won the Coppa Acerbo for Auto Union and Mercedes recovered to take the Swiss Grand Prix and Spanish Grand Prix, with Caracciola's victory at Lasarte clinching the European Championship. Rosemeyer won the Masaryk Grand Prix at Brno in his first grand prix victory, beating Nuvolari by over six minutes.
Caracciola's championship was built on consistent scoring across five events. Fagioli remained combustible in the garage and effective on track. Nuvolari's Nürburgring performance defined the season's narrative. Rosemeyer, just 25, emerged as the most exciting new talent in European motor racing.
The 1935 season confirmed that the Italian manufacturers, for all their ingenuity, could not match the engineering investment and pace of development the German teams could sustain. The Tipo B recorded its final Grand Prix victory at the Nürburgring — fittingly driven by the man who had coaxed the most from it throughout its career. The arrival of Rosemeyer signalled that Auto Union's junior driver programme would continue to challenge Mercedes' internal supremacy, setting up the rivalry that would define the following two seasons.