Mercedes-Benz
380 (W 22) Spezial-Roadster / 380 K one-offs

Why it matters

The 380 (W 22) was the supercharged eight-cylinder Mercedes-Benz of 1933 that carried an independent front suspension with wishbones and coil springs, together with a swing rear axle. It sat between the older six-cylinder S-series and the 500 K, and only 154 were built across all bodies and engine versions. Any special-bodied roadster on this chassis therefore starts from a very small base.

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 380 was unveiled in February 1933 at the Berlin motor show. Its engine went through three versions within a year: a side-valve eight that disappointed, an overhead-valve rebuild with 90 hp (120 hp with a built-on supercharger), and then an integrated, standard supercharger rated 90/140 hp, followed by a bore increase to about four litres. The engine, radiator, steering and front seats were moved rearward on the chassis to give a sportier stance. The 500 K replaced the 380 from February 1934 and the last 380 was produced in July 1934.

Factory body choices were a four-door saloon, Convertibles A, B and C, a roadster and an open tourer, or a bare chassis for an independent coachbuilder. The archive counts 54 Convertible B, 44 Convertible C, 16 Convertible A, 11 tourers, 7 roadsters, 6 saloons and 19 chassis, which adds up to 157 bodies against 154 chassis; it attributes the three extra to replacement bodies.

Two auction catalogues describe a two-seat 380 K Sport Roadster on chassis 102202. RM Sotheby's (London 2013) called it the most exclusive 380 K body style and put the number built at about 15, but added a note that the roadster was modified into its present form by Franz Prahl. Artcurial later described the body as possibly the work of Prahl on a 380 K chassis and engine base. The car is therefore a later conversion rather than a factory body.

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.

A factory 380 has the pointed Mercedes-Benz radiator, Rudge wire-spoke wheels and a box-section frame with a rearward-set engine and drivetrain. Unlike the S-series and the 500 K it has no outboard exhaust pipes trimmed in metal tubing, although that feature is often wrongly assumed to belong to all supercharged Mercedes-Benz cars. The supercharged engine is the M 22 K with integrated Roots supercharger.

Treat special roadster bodies with caution: the Sport Roadster on chassis 102202 shown at RM Sotheby's and Artcurial is documented as modified by Franz Prahl, Artcurial notes that Portuguese registration papers carry a German TÜV number (TPBW311074) where the chassis number 102202 should be, and RM reported that the Mercedes-Benz Classic Center could find no information on the VIN submitted. Verify any claimed one-off against the factory build records.

Sources

Each number links to the exact facts it supports.

1. 1
   380 (M 22 K engine with integrated supercharger) / W 22, 1933 - 1934 Level A Mercedes-Benz Public Archive (Classic M@RS)

   • Units produced : a total of 154 (all engine versions)
   • Engine type : M 22 K (Specifications)
   • Number of cylinders / arrangement : 8 / in line (Specifications)
   • Total displacement : 3823 cc (tax classification: 3796 cc) (Specifications)
   • Bore x Stroke : 78 x 100 mm (Specifications)
   • Compression ratio : 5.54 (Specifications)
   • Valve operation : 1 lateral camshaft; Camshaft drive : via spur gears (Specifications)
   • Fuel system : 1 Mercedes-Benz special updraught twin carburettor / Roots supercharger (Specifications)
   • Combustion principle : ... carburettor engine with integrated Roots supercharger (Specifications)
   • Rated output : 90 hp at 3200 rpm, with supercharger 140 hp at 3600 rpm (Specifications)
   • with supercharger 140 hp at 3600 rpm (Specifications)
   • Gearing : 3-speed gearwheel thrust transmission with additional overdrive (Specifications)
   • Gear ratios : I: 2.86; II: 1.80; III: 1.0; S: 0.70 (Specifications)
   • Final drive ratio : 5.11 or 4.70 (Specifications)
   • Driven wheels : rear wheels (Specifications)
   • Frame design : box-section pressed-steel low-bed frame (Specifications)
   • Front-wheel suspension : double wishbone; Front springs : coil springs (Specifications)
   • Rear-wheel suspension : swing axle; Rear springs : double coil springs (Specifications)
   • Brake system (foot brake) : hydraulic, acting on front- and rear wheels (Specifications)
   • Steering : worm-and-nut steering (Specifications)
   • Wheelbase : 3140 mm (Specifications)
   • Length : 4690 mm (Specifications)
   • Width : 1730 mm (Specifications)
   • Height : 1620 mm (Specifications)
   • Front / rear track : 1435 / 1480 mm (Specifications)
   • Kerb weight : cabriolet C: 2100 kg (Specifications)
   • Chassis weigth : 1350 kg (Specifications)
   • Maximum speed : 135 km/h (rear-axle 5.11) or 145 km/h (rear-axle 4.70) (Specifications)
   • Fuel tank: position / capacity : in the rear / 85 l (Specifications)
   • Fuel consumption : 23 l (Specifications)

   Accessed 2026-11-12
2. 2
   1933 Mercedes-Benz 380 K Erdmann & Rossi Spezial Roadster Specifications - Ultimatecarpage.com Level C

   • 1 Erdmann & Rossi Spezial Roadster: car built

   Accessed 2026-11-11