Mercedes-Benz
W 125 Rekordwagen

Why it matters

The W 125 record car was a fully streamlined, V12-powered Mercedes-Benz built for the German record weeks of 1937 and 1938. In its revised 1938 form Rudolf Caracciola covered the flying kilometre at 432.692 km/h on a public road, a mark that stood for almost eight decades until it was beaten in November 2017 at 445.54 km/h. Wind-tunnel measurements decades later gave its body a drag coefficient of only 0.157, remarkable even by modern standards.

How rare is it?

Six separate kinds of rarity – never combined into one number.

Each kind of rarity is rated separately and never combined.

Production

Every figure says what it counts.

Independent counts (e.g. engine and colour) are never combined into a calculated figure. Surviving examples are never presented as original production.

History

The car combined the chassis of the new W 125 Grand Prix car with a new streamlined body and a 5.6-litre V12 aircraft-style racing engine, the MD 25 DAB, designed by Albert Heess from 1935. At the first record week on 25 October 1937 the car reached 366 km/h over the flying kilometre, then could not run at full throttle because the front lifted; a defective piston ended the attempt. A second try three days later, with a 46 kg lead weight on the front axle, gave 398.89 km/h, but the engine ran poorly again and Daimler-Benz withdrew, while Auto Union reached 406.3 km/h.

After the failure the aerodynamics were reviewed with experts from the German aircraft industry and the DVL research institute. The new body was lowered at the front, shortened by 80 mm at the nose and lengthened by 500 mm at the tail, and the large radiator opening was replaced by two small carburettor air intakes, because ice cooling replaced a radiator for short runs. The same engine, serial number 3, was reworked to around 765 hp at 5800 rpm.

On 28 January 1938 Caracciola averaged 432.692 km/h over the flying kilometre and 432.361 km/h over the flying mile, with a one-way top speed of 437 km/h. Auto Union tried to beat the mark the same day, but Bernd Rosemeyer was killed in his attempt after a crosswind gust. The 1938 figure was a public-road record until 4 November 2017.

Technical specifications

Engine

Transmission & drivetrain

Chassis, body & dimensions

Performance

“Not yet verified” means no source has been checked for that value yet. Nothing is estimated to fill a gap.

Identification guide

How to tell an original from a replica or later conversion.

The 1938 car can be told from the 1937 version by its lowered front end with two small oblong-round carburettor intakes instead of one large cooling opening, a body 80 mm shorter at the nose and 500 mm longer at the tail, a waisted body that reduces crosswind area, and a rounded, strongly raked, dome-like cockpit screen. It has no conventional radiator, since the V12 used ice cooling for the short runs. The engine is the MD 25 DAB V12 with steel cylinders and welded-on sheet-steel cooling jackets, serial number 3, on a chassis derived from the W 125.

Sources

Each number links to the exact facts it supports.

1. 1
   Sports Car Digest – Mercedes-Benz W 125 Streamliner: Photos, Profile, History Level C

   • 1 Individual car: the 1938 streamlined V12 W 125 record car; as stated: “The original vehicle is now showcased at the Mercedes-Benz Museum in Stuttgart” (also described on the Mercedes-Benz Classic archive page, which carries no figure)

   Accessed 2026-11-11
2. 2
   Mercedes-Benz W 125 record car, 1938 (Classic M@RS) Level A Mercedes-Benz Group AG (Classic M@RS, Mercedes-Benz Public Archive)

   • V12 engine, designated MD 25 DAB
   • nearly 5.6-litre V12 engine, designated MD 25 DAB
   • nearly 5.6-litre V12 engine
   • the nearly 5.6-litre V12 engine, designated MD 25 DAB
   • further increase in power to around 765 hp/563 kW at the same rated speed
   • 765 hp/563 kW at the same rated speed of 5800 rpm
   • Averaging the outbound and inbound legs ... 432.692 km/h over the kilometre

   Accessed 2026-11-12
3. 3
   Mercedes-Benz W 125 record car, 1937 (Classic M@RS) Level A Mercedes-Benz Group AG (Classic M@RS, Mercedes-Benz Public Archive)

   • two float carburettors positioned between the blower and the air intake
   • The chassis was taken from the new W 125 Grand Prix racing car

   Accessed 2026-11-12