For the 1935 racing season, the Auto Union Grand Prix racing cars were refined in many details by the racing department at Zwickau, together with Ferdinand Porsche. The displacement of the engine was enlarged to just under 5 litres and the compression ratio increased, to boost the power output by 30 percent. A Hirth crankshaft on roller bearings allowed higher engine speeds, while a longer wheelbase and wider track provided for better roadholding. In addition, the rear leaf springs were replaced by longitudinal torsion bars.
Engine: 16-cylinder in V arrangement, with Roots supercharger
Displacement: 4,951 cc
Power: 375 hp at 4,800 rpm
Maximum speed: 295 km/h