Mercedes-Benz
W 25 Avus streamliner

Why it matters

For the formula-free AVUS race of May 1937, Mercedes-Benz converted two retired short-wheelbase W 25 Grand Prix cars into high-speed machines by installing the 5.6-litre MD 25 DAB V12 and fitting a fully enclosed body. The streamlined W 25 reached up to 380 km/h on the long straights. It is also one of the few uses of the V12, which was too heavy for the 750 kg formula and was otherwise used mainly for record runs.

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 MD 25 DAB V12 was designed by Albert Heess from the start of 1935 as a successor to the straight-eight, but at almost 295 kg it was too heavy for the 750 kg formula. In autumn 1936 the racing department reactivated two shortened W 25 chassis for the 1937 AVUS race and fitted the V12 to both. On the test bench in autumn 1937 it gave 679 hp with float carburettors ahead of the blowers and 736 hp with slide carburettors; in the AVUS race car, with pressure carburettors after the blowers, the output was 616 hp at 5800 rpm.

The frame and the de Dion axle tube had to be strengthened, the frame was lengthened at both ends, and the car received much larger 22-inch front and 24-inch rear wire wheels instead of 17 and 19 inches. The streamlined body added around 200 kg. Manfred von Brauchitsch won his qualifying heat, but in the final he managed only half a lap before a gearbox oil line failed. The second V12 W 25, meant for Goffredo Zehender, suffered irreparable engine damage in practice. The race was won by Hermann Lang in a streamlined W 125.

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 AVUS W 25 is a shortened 750 kg-formula W 25 chassis with a lengthened frame, a strengthened de Dion rear axle tube and a fully enclosed streamlined body. It uses 22-inch front and 24-inch rear wire wheels, against 17 and 19 inches on the Grand Prix car, and is about 200 kg heavier. The engine is the MD 25 DAB V12 with a 60-degree bank angle, 82 x 88 mm bore and stroke, two sets of two overhead camshafts, four valves per cylinder and forked connecting rods that leave the two banks parallel rather than slightly offset.

Sources

Each number links to the exact facts it supports.

1. 1
   Mercedes-Benz W 25 SWB AVUS racing car with streamlined body, 1937 (Classic M@RS) Level A Mercedes-Benz Group AG (Classic M@RS, Mercedes-Benz Public Archive)

   • reactivated two of the shortened W 25 chassis
   • V12 engine with the designation MD 25 DAB
   • cylinder bank angle of 60 degrees
   • twelve-cylinder engine, which had a capacity of 5.6 litres
   • The dimensions for bore and stroke of 82 x 88 mm
   • two times two overhead camshafts and four valves per cylinder
   • traditional pressure-tight carburettors downstream of the Roots blowers
   • 616 hp/453 kW at 5800 rpm
   • the frame had to be lengthened at both front and rear
   • reached speeds of up to 380 km/h on the long straights

   Accessed 2026-11-12
2. 2
   1937 Mercedes-Benz W25 Avus Streamliner Specifications - Ultimatecarpage.com Level C

   • 2 cars built

   Accessed 2026-11-11