Mercedes-Benz W196

Mercedes-Benz W 196 "Typ Monza"

Karl Kling driving W 196 at Nürburgring

The Mercedes-Benz W196 was the Formula 1 entry of Mercedes-Benz in the 1954 Formula One season and 1955 Formula One season, winning 9 of 12 races at the hands of Juan Manuel Fangio and Stirling Moss.
Its delayed debut on the 1954 French Grand Prix brought the streamlined "Typ Monza" body for the high speed track at Reims-Gueux (and later Monza), and scored a 1-2 victory with Fangio and Karl Kling plus a fastest lap with youngster Hans Herrmann.
Another remarkable first was the use of Desmodromic valves and fuel injection, based on previous experience collected with the engines of the Messerschmitt Bf 109 fighters. As the streamlined body was not situable for twistier tracks, causing a defeat at its second race at Silverstone, a proper open-wheel-version was introduced at the Nürburgring. Fangio, who had already won the first two GPs of 1954 with a Maserati, won this and the two following GPs, securing his 2nd World Championship. In late October, at the 1954 Spanish Grand Prix, the low-mounted Mercedes air-intake was clogged with leaves. The race was lost, and the air-intake moved to the top of the hood.
In the 1955 Formula One season, which was shortened after the 1955 Le Mans disaster, the Mercedes managed to win all but one race, the 1955 Monaco Grand Prix, where Hans Herrmann crashed in practice, and the other 3 cars did not finish. At his 1955 British Grand Prix home event, Stirling Moss finished 0.2 seconds ahead of Fangio for his first GP win.
For sportscar races of the 1955 World Sportscar Championship season, the Mercedes-Benz 300 SLR was derived from it.
The new 1954 Formula 1 rules allowed engines of 2.5 litres unsupercharged or alternatively 0.75 supercharged. The 1939 Mercedes 2-stage supercharged 1.5 litre 64.0 x 58.0 mm V8 (1493 cc/91.1 cuin) gave 278 bhp at 8,250 rpm with about 2.7 ata pressure. Halving this would have only given 139 bhp. The expected target range for competitive engines was 250 to 300 bhp. Studies by Mercedes showed that 290 bhp at 10,000 rpm could be achieved from 0.75 litres with a supercharger pressure of 4.4 ata. 390 shp would have been developed with 100 hp being required to drive the supercharger. Fuel consumption would have been 2.3 times higher than an unsupercharged engine developing the same power. Since 115 bhp/litre at 9,000 rpm was being developed by unsupercharged motorcycle racing engines, it was decided that a 2.5 litre engine was the correct choice. This was a significant change of philosophy, since all previous Mercedes-Benz Grand Prix engines since the 1920s had been supercharged.
The 2,496.87 cc (152.4 cuin) straight 8 (76.0 x 68.8 mm) gave 257 bhp at the 1954 French GP which was its first race. During 1955 this had increased to 290 bhp at 8,500 rpm. The 2,981.70 cc (181.95 cuin) sports car (78.0 x 78.0 mm) gave 310 bhp at 7,500 rpm and was a bored and stroked version of the F1 engine complete with desmodromic valves and fuel injection. Variable length inlet tracts were experimented with and four wheel drive considered. An eventual 340 bhp at 10,000 rpm was targeted for the 2.5 litre F1 motor.
After winning all three world championships it competed in, Mercedes withdrew from motorsport at the end of the 1955 season.