The Mercedes 300SL Gullwing coupe was arguably the best and most famous race car of its time. It was the first real high-performance mass-produced sports car in the world. At the time, it was the fastest production car and could achieve a top speed of 263 km/h.
300SL W194
Everything began in 1952 with the Ur-300SL with the internal Mercedes designation of W194. The first prototypes had narrow Gullwing doors whit the sills reaching all the way up to the waist. The doors and high sills weren't a design feature but necessary due to the underlying spaceframe which keeps the car as light and rigid as possible. The idea originated from Rudolf Uhlenhaut who at the time was Mercedes racing director. It's said that he fabricated a spaceframe model at home with soldering iron and wires until he found the perfect construction that wouldn't bend anymore but only collapse under pressure.
The engine was taken from the heavy Mercedes 300 sedan. Everything needed a lightweight treatment to bring down the engine's weight to racing specifications. The heavy cast iron engine block was used during WWII in commercial vehicles and was way too heavy for a racing application. Mercedes engineers didn't find much weight savings with the engine but instead compensated with the ultra-light space frame, an ultra-thin aluminium body and acrylic windows.
The W194 was presented to the public on the 12th of March 1952 on a section of the German Autobahn 81 between Heilbronn and Stuttgart. On the 1st of April 1952, the spaceframe of Chassis No.5 was just completed on time for the Mille Miglia race on the 3rd of May. The car entered the race as No.613 and scored place four with Rudolf Caracciola at the helm and Paul Kurrle as co-driver. Karl Kling and Hans Klenk cross the finishing line with Chassis No.4 second and win a podium place.
The first iteration of the Mercedes-Benz 300 SL, codenamed W194 then won two of the most prestigious races in the world - the 24 Hours of Le Mans and the Carrera Panamericana. All of this happened in the 1952 racing season which was a very important moment in the brand's motorsport history.
Chassis 007/52 (Hermann Lang/Fritz Riess) is the 1952 Le Mans winning car, making it the only win for Mercedes at the French 24-hour endurance race (the 1989 race goes to Sauber as they built the car while Mercedes sourced the engine). Mercedes achieved a 1-2 win with chassis 009/52 (Theo Helfrich/Helmut Niedermayr) in second place, in a field featuring several Jaguar C-Types, Aston Martin DB3s and a lot of Ferrari competitors.
Chassis No.5 went on to race at the grand prize of Bern where Caracciola crashed, and his racing career ended. No.5 was then restored and shipped to Mexico along with No.4 to be entered at the 3rd Mexican Carrera Panamericana. Both cars went on to win first and second with pilots Karl Kling and Hermann Lang. A triumphant double.
Chassis 0005/52 (Hermann Lang/Erwin Grupp), 0008/52 (Karl Kling/Hans Klenk) and 0009/52 (John Fitch/Eugen Geiger) but 0009, now an open-top car, did not finish, while 0008 won with 0005 finishing second, 35 minutes after the winner. Chassis 0008 is exhibited at the Mercedes-Benz Museum permanently while chassis 0007 is currently part of the centenary exhibition at the 24h of Le Mans Museum until the end of Le Mans Classic.
These successes of the W194 were very surprising because the car was at the time already very underpowered and its 2996cc engine only produced 175 HP with its three Solex downdraft carburettors. This was considerably less than the competing Ferraris and Jaguars which boasted already +200 HP. The factor of low weight (dry weight only 870kg) and good aerodynamics made the car competitive enough to win endurance races.
Technical Details
The engine was tilted 50 degrees to the left side to keep the bonnet as flat as possible. Mercedes continued this with the later W198 series-production sportscar.
Displacement | 2996cc | Top Speed | 240 km/h |
Engine | Inline-6 OHC / 2 valves per cylinder | Consumption | 20l/100km |
Power Output | 175 HP / 125kW @ 5200 rpm | Dry weight | 870 kg |
Torque | 249Nm at 4100 rpm | Suspension | Independent suspension with coil springs |
Transmission | Manual four-speed with rear axle transmission lock | Fuel delivery | 3 Solex downdraft carburettors |
300SL Der Hobel / The Plane
For the 1953 season, the W194 received a facelift and a couple of upgrades. This model still bears the same internal designation of W194 but is unofficially named "Der Hobel" meaning the "carpenter's plane" due to its distinguished flat bonnet. Only one single car which is chassis No.11 was built. The car today still belongs to the Mercedes-Benz Museum. The car received a body made from "Elektron" which is a magnesium alloy that is even lighter than aluminium. The engine now featured direct injection putting out 215 HP and the transmission was now of a transaxle type for better weight distribution.
It was never entered in a competitive race due to the upcoming entry of Mercedes-Benz into Formula 1 which was planned for 1954 and tied up all racing capacities. Though, it did pave the way for the 300 SL Gullwing series production sports car which also featured direct fuel injection. The "Hobel" has remained in the company's possession ever since 1952.
300SL W198 I Coupe
In February of 1954, Mercedes-Benz presented the series production sportscar 300SL Gullwing at the International Motor Sports Show in New York City. The car was conceived by US importer Max Hoffman who was inspired by the W194 300SL and saw an American market for a German supercar. It was intended for the wealthy performance car enthusiasts in the US where the market for the personal luxury car was booming after the Second World War. Desperate for a sportscar to sell to his wealthy clientele, Hoffman eventually persuaded the Daimler-Benz board to take the 300SL from the racetrack to the road. The designers and engineers refused to compromise on the purity of the original, so the bodywork was still primarily crafted to reduce drag as much as possible. Although rumour has it that the elegant strips over the wheel arches were no more than fashionable cosmetic touches to make the car appeal to its American audience.
Hoffman also imported BMWs and persuaded the BMW management to produce a roadster version of the BMW 501 and BMW 502 saloons to fill the gap between the expensive Mercedes-Benz 300SL and the cheap and underpowered Triumph and MG sports cars. The resulting 507 was a big blow for BMW due to runaway production costs. In the end, only 252 cars left the factory.
The series Gullwing sports car features a 3.0L engine boasting now 215HP and a top speed of 260km/h which made it the fastest production car at the time. It cost 29'000 Deutsche Mark which could have bought you over six VW Beetles. The chassis and body were manufactured from steel but a special "Leichtbau" upgrade was available with a full aluminium body. In Total 1'400 cars were produced between 1954 and 1957 with only 29 cars featuring the lightweight alu upgrade.
Technical Details
Displacement | 2996cc | Top Speed | 263 km/h |
Engine | Inline-6 OHC / 2 valves per cylinder | Consumption | 17l / 100 km |
Power Output | 215 HP / 158kW @ 5,800 rpm | Dry weight | 1'500 kg |
Torque | 275 Nm @ 4,600 rpm | Suspension | Front: double wishbone coils Rear: swing axle |
Transmission | 4-speed manual | Fuel deliery | mechanical direct fuel injection |
300SLR W196S
The Mercedes-Benz 300 SLR W196S was a 2-seat sports racer that competed in the World Sportscar Championship before a catastrophic crash and fire at Le Mans ended its career prematurely. The W196S and its 3.0L engine were derived from the Mercedes Formula 1 W196 racing car and didn't have much in common with the series production W198. It shared most of its drivetrain and chassis with the 196's fuel-injected 2.5L straight 8's and boosted 266HP. It was designated "SL-R" for Sport (or Super) Leicht-Rennen / Sport Light-Racing and later condensed to just SLR.
Stirling Moss and co-driver Denis Jenkinson won with the W196S the 1955 Mille Miglia and set a record of 10:07:48 hours which stands to this day. The 300 SLR racer was the car that won almost everything in 1955, from Mille Miglia to Targa Florio, allowing Mercedes-Benz to win the 1955 World Sportscar Championship. Its light aluminium body, exceptional handling and extreme acceleration made it one of the iconic cars of the 50s. And its winning streak would have continued as a coupe in 1956 because Daimler-Benz developed a hardtop version for the new season.
Unfortunately, Mercedes racing streak came to a sudden end on the 11th of June 1955 during the 24 Hours of Le Mans motor race in France. It is considered the deadliest accident in motorsport history with 84 spectators killed and at least 100 more injured after an Austin-Healey and a Mercedes-Benz 300SLR collided. Large pieces of deadly debris flew into the crowd. Mercedes chose to end its motorsport activities at the end of the 1955 season and only returned to Le Mans again in 1987.
This crash was also responsible for Switzerland's ban on motorsports which lasted up until 2015 when the Swiss only made an exemption for electric vehicles with the first Formula E race held in 2018.
Technical Details
Displacement | 2,982 cc | Top Speed | 290 km/h |
Engine | Straight-8 OHC / 2 valves per cylinder | Consumption | N/A |
Power Output | 276 HP / 203 kW @ 7000/min | Dry weight | 901 kg |
Torque | 311Nm @ 5950 rpm | Suspension | double wishbone, torsion bar springs, telescopic shock absorbers |
Transmission | 5-speed transaxle | Fuel delivery | |
300SLR Uhlenhaut Coupe
For the 1956 racing season Mercedes had developed already a closed coupe racing version of the 300 SLR W196S but it didn't see the track anymore. Only two cars were built and the head of the test department, Rudolf Uhlenhaut, decided to use one of the two completed 300SLR coupe vehicles as a company car. The nickname "Uhlenhaut Coupe" is a reminder of this. Over the years, people testing it said it was even better than the 300 SLR racer and today you can see it racing only at special events and in the Mercedes-Benz museum.
The car also made headlines in 2022 when one of the two cars was auctioned off by RM Sothebys for a staggering €135.000.000. The auction made the 300SLR Uhlenhaut Coupe the most expensive car in the world. Before the Uhlenhaut Coupe, the most expensive car ever sold at auction was a 1962 Ferrari 250 GTO which sold in 2018 for $48 million, also through RM Sotheby. The sale of the Uhlenhaut Coupe took place on May 5th 2022 in a highly unusual auction held at the Mercedes-Benz Museum.
According to Simon Kidston, the top-secret auction only lasted just 19 minutes and 30 seconds to sell “the Mona Lisa of cars”. Simon also said: “More tellingly, though, not once has the buyer asked me what I think it might be worth in the future. It was just a lifelong dream come true.”It is one of the two 1955 Mercedes-Benz 300 SLR Uhlenhaut Coupés ever made and the car was sold to a private collector.
300SL W198 II Roadster
By 1957, 300SL sales were on the slide. Feedback from customers suggested that they'd like more comfort and a larger trunk. Maxi Hoffman helped convince Mercedes-Benz that a convertible version could take over where the coupe left off. Introduced at the Geneva Motor Show in 1957, the 300SL Roadster wasn't the result of a quick fix to meet owner demands. Mercedes re-engineered the whole car, taking the opportunity to fix some issues that plagued the 300SL, first of all, the suspension. The fantastic 3.0L straight-six was tuned from 215 HP to 225 HP, and the chassis was redesigned with lower sills to accommodate normal swing-opening doors.
The roadster combined the sophisticated engineering of a car that was very advanced for its day with the enjoyment of relaxed open-top driving. Its six-cylinder injection engine was derived from competition racing and ensured an outstanding performance, technical qualities and a high level of luxury and comfort. Although, the roadster wasn't a pure drivers and racing car anymore due to its heavier weight (125kg more than the 300SL Coupe) and worse aerodynamics. At the time, it rivalled the BMW 507 roadster and the Ferrari 250 California, that were also leisure sportscars for the wealthy. The car was sold until 1963 for an MSRP of 32'500 Deutsche Mark, and a total of 1858 cars were produced.
The SL Name
At the public introduction of the 300 SL in 1952, Mercedes-Benz did not define the abbreviation SL. Ever since Mercedes fans were speculating if the "S" stood for "Super" or for "Sport". The letter L was always clear because the 1931 racing car SSKL received a drastic weight-reduction treatment leading to the "Leicht" or "Light" abbreviation, which was also important with the W194. A reputable media outlet then used the "Sport" translation, referencing the father of the 300SL Rudolf Uhlenhaut, who mentioned it in a notarised letter. Mercedes-Benz used Sport Leicht and Super Leicht interchangeably until 2017, when a chance discovery in its corporate archive clarified the abbreviation stood for "Super Leicht". In 2017 a Mercedes employee discovered an official document in the archives which brought the truth to light. At the time, one of Mercedes archivists had glued newspaper cuttings on the back page of A4 documents. One of these snippets was a 1952 press release where the abbreviation was translated to "Super Leicht".
Photos: Mercedes-Benz Group Media
Nils Willner
Nils is a Swiss-German engineer who is obsessed with old cars and engines. He is the author of "The Ultimate Classic Car Guide - How to Buy, Maintain & Repair Classic Cars" and the founder of EVC. My passion has always been with old cars and everything that has wheels and an engine.
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