1937: Second Championship
Mercedes-Benz returned to Grand Prix racing at the start of the 1937 season with a new car. The W125 was a vast improvement on its predecessor, its supercharged eight cylinder 5.6-litre engine delivered significantly more power than the W25: 650 brake horsepower compared to 500. The first major race of 1937 was the Avusrennen where 300,000 people turned out to see the cars race on the newly re-constructed track. In order to keep speeds consistently high, the north curve was turned into a steeply banked turn, apparently at the suggestion of Adolf Hitler. Driving a streamlined Mercedes-Benz, Caracciola won his heat against Rosemeyer, averaging around 250 kilometres per hour (160 mph), although a transmission failure forced him to retire in the final. Following the AVUS race, Caracciola, along with Rosemeyer, Nuvolari and Mercedes' new driver, Richard Seaman, went to race in the revived Vanderbilt Cup in America, and in doing so missed the Belgian Grand Prix, which took place six days later. Caracciola led until lap 22, when he retired with a broken supercharger.
Caracciola started from the second row of the grid at the German Grand Prix, but was into the lead soon after the start. There he remained to the finish, in front of von Brauchitsch and Rosemeyer. He took pole position at the Monaco Grand Prix three weeks later, and was soon engaged in a hard fight with von Brauchitsch. The Mercedes-Benz drivers took the lead from each other several times, but von Brauchitsch won after a screw fell into Caracciola's induction system during a pit stop, costing him three and a half minutes. Caracciola won his second race of the season at the Swiss Grand Prix. Despite heavy rain which made the Bremgarten Circuit slippery and hazardous, Caracciola set a new lap record, at an average speed of 169 kilometres per hour (105 mph), and cemented his reputation as the Regenmeister.
For the first time, the Italian Grand Prix was held at the Livorno Circuit rather than the traditional venue of Monza. Caracciola took pole position, and despite two false starts caused by spectators pouring onto the track, held his lead for the majority of the race and won from his teammate Lang by just 0.4 seconds. In doing so Caracciola clinched the European Championship for the second time. He backed up the win with another at the Masaryk Grand Prix two weeks later. He trailed Rosemeyer for much of the race until the Auto Union skidded against a kerb and allowed the Mercedes into the lead.
Caracciola married for the second time in 1937, to Alice Hoffman-Trobeck, who worked as a timekeeper for Mercedes-Benz. He had met her in 1932, when she was having an affair with Chiron. She was, at that time, married to Alfred Hoffman-Trobeck, a Swiss businessman and heir to a pharmaceutical empire. She had taken care of Caracciola after Charlotte died, and shortly after began an affair with him, unbeknownst to Chiron. They were married in June in Lugano, just before the trip to America.
Read more about this topic: Rudolf Caracciola