Mercedes-Benz
300 SLR (W 196 S) "722" – 1955 Mille Miglia winner

Why it matters

This is the 300 SLR (W 196 S) that won the 1955 Mille Miglia with Stirling Moss and co-driver Denis Jenkinson, running with start number 722. The 300 SLR was the sports-car counterpart of the W 196 R Grand Prix car, with the engine enlarged to three litres, and it carried Mercedes-Benz to the 1955 Sports Car World Championship. The Mille Miglia average of 157.65 km/h was never surpassed in the race.

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 300 SLR was developed from autumn 1953 in parallel with the W 196 R Formula 1 car. Work on it was paused in spring 1954 so that the racing department could concentrate on Formula 1, and it received its finishing touches in late summer 1954. Drivers preferred an open car to the originally planned coupé, so only the roadster started in 1955, and its racing debut was the 1955 Mille Miglia.

Moss and Jenkinson won the 1000-mile race in 10 hours, 7 minutes and 48 seconds, at an average of 157.65 km/h. Juan Manuel Fangio, who drove without a co-driver, was second with start number 658. The type went on to win the Eifel race, the Swedish Grand Prix, the Tourist Trophy and the Targa Florio, and the 1955 season ended with the Le Mans accident involving Pierre Levegh's 300 SLR. Daimler-Benz announced its withdrawal from racing on 22 October 1955.

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 archive page does not give a chassis number for the Mille Miglia winner, so identification rests on the race record and the type's specification. The car ran with start number 722 and was the open two-seater version. Type-level features given by the archive are a three-litre straight-eight made of two four-cylinder blocks with centre output and light-metal blocks, rated 306 hp (225 kW) at 7500 rpm and running on normal premium petrol, a tubular frame of about 60 kg, a double-wishbone front axle with torsion-bar springs, a single-joint swing axle at the rear, large inboard drum brakes, and a wheelbase 20 mm longer than the W 196 R. The archive adds that an air brake flap was fitted to the cars for Le Mans and the Swedish Grand Prix.

Sources

Each number links to the exact facts it supports.

1. 1
   Sports Car Digest – Mercedes-Benz 300 SLR racing sports car "722" (Mercedes-Benz Classic Communications) Level C

   • 1 Individual car: “the Silver Arrow with which Stirling Moss and Denis Jenkinson won the Mille Miglia” (Mercedes-Benz Classic press text, 70th anniversary)

   Accessed 2026-11-11
2. 2
   Mercedes-Benz 300 SLR (W 196 S), 1955 Level A Mercedes-Benz Public Archive (Classic M@RS)

   • two separate four-cylinder blocks with a centre output
   • three-litre version of the in-line eight-cylinder engine
   • 306 hp/225 kW at 7500 rpm
   • extremely light but at the same time very torsionally rigid tubular frame
   • The double wishbone front axle featured the tried-and-tested combination of trapezoidal links
   • a single-joint swing axle served as the rear axle
   • The inboard brake drums

   Accessed 2026-11-12