Mercedes-Benz W125

Mercedes-Benz W125
CategoryGrand Prix
ConstructorMercedes-Benz
Designer(s)Max Sailer
Albert Heess
Max Wagner
Rudolf Uhlenhaut
PredecessorMercedes-Benz W25
SuccessorMercedes-Benz W154
Technical specifications
ChassisTubular frame
Suspension (front)Independent suspension with wishbones, coil springs, hydraulic dampers
Suspension (rear)De Dion axle, torsion bars, hydraulic dampers
EngineMercedes-Benz M125 5.663 litre Straight-8 supercharged
TransmissionMercedes-Benz 4-speed transverse
FuelMethanol/benzole blend
Competition history
Notable entrantsDaimler-Benz AG
Notable driversManfred von Brauchitsch
Rudolf Caracciola
Hermann Lang
Richard Seaman
Debut1937 Tripoli Grand Prix
RacesWinsPolesF/Laps
12666
Drivers' Championships1

The Mercedes-Benz W125 was a Grand Prix racing car produced by German auto manufacturer Mercedes-Benz to race during the 1937 Grand Prix season. Designed by head designer Rudolf Uhlenhaut, the car was used by Rudolf Caracciola to win the 1937 European Championship and W125 drivers also finished in the second, third and fourth positions in the championship.[1]

The W125 was powered by a supercharged double overhead camshaft 5,663 cc (345.6 cu in) capacity 94 mm × 102 mm (3.70 in × 4.02 in) inline 8 which produced 595 hp (444 kW) in race trim. Its highest test bed power measured was 637 BHP (646 PS) at 5,800 rpm, with 245 BHP (248 PS) developed at a mere 2,000 rpm. In 1938, the engine capacity of supercharged Grand Prix cars was limited to 3000cc, and the W125 was replaced by the Mercedes-Benz W154.

The W125 was considered the most powerful road racing car ever for three decades until large capacity American-built V8 engines in CanAm sports cars reached similar power in the late 1960s. In Grand Prix racing itself, the figure was not exceeded until the early 1980s (when Grand Prix racing had become known as Formula One), with the appearance of turbo-charged engines.[2]

The W125 reached race speeds of well over 300 km/h (190 mph) in 1937, especially on the AVUS in Berlin, equipped with a streamlined body.

In land speed record runs, a Mercedes-Benz W125 Rekordwagen was clocked at 432.7 km/h (268.9 mph) over a mile and a kilometre. This car was fitted with a DAB V12 engine (82 x 88 mm) of 5,576.75 cc (5.6L, 340.31 CID) with a power of 726 hp (736 PS) at 5,800 rpm. The weight of this engine caused the car to weigh over the 750 kg maximum limit, so it never appeared in Grand Prix.

  1. ^ DK (2015-09-01). Cars Trains Ships and Planes. Dorling Kindersley Limited. ISBN 9780241245286.
  2. ^ Carter, Anthony (2011-10-15). Motor Racing: The Pursuit of Victory 1930–1962. Veloce Publishing Ltd. ISBN 9781845842796.