The Mercedes-Benz W196 (sometimes written as the Mercedes-Benz W 196 R) was a Formula One racing car produced by Mercedes-Benz for the and F1 seasons. Successor to the W194, in the hands of Juan Manuel Fangio and Stirling Moss it won 9 of 12 races entered and captured the only two world championships in which it competed.
Firsts included the use of desmodromic valves and Daimler-Benz developed mechanical direct fuel injection adapted from the DB 601 high-performance V12 used on the Messerschmitt Bf 109E fighter during World War II.
The 3-litre 300 SLR was derived from the W196 for the 1955 World Sportscar Championship season. Its crash at Le Mans that year ended not only its own short-lived domination but also spelled the end for the W196, as Mercedes pulled out of competitive racing in 1955 and did not return for another three decades.
Types
Monza
The W196's delayed debut at the 1954 French Grand Prix saw the introduction of the aerodynamic closed-wheel aluminium "Type Monza" streamliner body for the high speed track at Reims. Juan Manuel Fangio and Karl Kling claimed a 1–2 finish, and Hans Herrmann posted the fastest lap. The same body was later used only three more times: in the season at the British Grand Prix at Silverstone and the Italian Grand Prix at Monza, where it picked up its nickname, and in the season again at the Italian Grand Prix at Monza. In total the "Type Monza" won three races (the 1954 French Grand Prix, 1954 and 1955 Italian Grand Prix), all with Fangio at the wheel. These three Grands Prix have remained the only races won by a closed-wheel car in Formula One history.
Open wheel
Attractive as the Monza was, its streamlined body was really only suited to high-speed tracks made up of straights and slow corners, leading to defeat at its second race, the British Grand Prix at the high-speed corner dominated Silverstone circuit, where Fangio hit a number of oil barrels that marked out the circuit. A conventional open-wheel-version was introduced for the most important race on the calendar for Mercedes, the German Grand Prix at the twisty and long Nürburgring. Fangio, who had already won the first two GPs of 1954 with a Maserati in his home city of Buenos Aires and at Spa, won this and the two following GPs in Switzerland with the 'open wheel' version and Italy, as said, on the closed-wheel streamlined 'Type Monza', securing his 2nd World Championship.
At the Spanish Grand Prix in Barcelona, the last race of the 1954 season the low-mounted Mercedes air-intake clogged with leaves, costing the race to Mike Hawthorn in a Ferrari, and leading to the intake's relocation atop the hood.
In the shortened 1955 Formula One season, abbreviated after the Le Mans disaster, the W196 won every race except the Monaco Grand Prix, where Hans Herrmann crashed in practice and the other three team Mercedes cars failed to finish. A highlight for driver Stirling Moss was his finish 0.2 seconds ahead of stable mate Fangio at his home event, the British Grand Prix, his first GP win, a race where Mercedes romped home with a 1–2–3–4 finish.
After capturing the two world championships it competed in, Mercedes withdrew from motorsport at the end of the 1955 season. Despite its strong reliability and good track performance, drivers Fangio and Moss described the car in MotorSport magazine as being "a bit difficult to drive, with a tendency for snap oversteer". Moss also later said that "I'm surprised that the Merc wasn't a little bit easier to drive, because it wasn't. It was a driver's car, but not an easy car to drive." Fangio shared similar feelings, also saying in MotorSport Magazine in 1979 that the car was "not so nice to drive as a Maserati 250F, but you were almost sure to finish. So the Mercedes was incredible in that way." 1970s/80s Formula One driver John Watson drove the W196 at Hockenheim, providing some insight as to why the car was difficult to drive. He said that "if you gave this car wider and grippier tyres and altered the suspension to suit, then the handling would be of a very high order indeed." The W196 was so advanced and ahead of its time, that the narrow tyres available at the time simply could not fully handle the car's exceptional performance and potential.
Engine
The new 1954 Formula One rules allowed a choice of naturally aspirated engines – up to 2.5 litres or 0.75 litres supercharged. The expected target range for competitive engines was .
Mercedes' 1939 2-stage supercharged 1.5-litre, bore/stroke: × V8 () gave at 8,250 rpm with about pressure. Halving this would have only produced .