The iconic postwar Mercedes convertible

The 300SL is often credited for being the world’s first “supercar.” Why? To start, it’s beautiful, with flowing lines that are both elegant and aerodynamic. Climb onboard, and you’ll find premium luxury and top-shelf opulence. But more importantly, there’s a good deal of technological innovation and racing pedigree hiding just under the skin, which blesses the 300SL with truly world-beating speed. Throw in low production numbers and the car’s high desirability amongst collectors, and the formula starts to come together.

Prior to 1954, Mercedes was seen as a luxury make without much to offer when it came to performance. The 300SL changed that in a hurry. The name is a reference to the engine displacement (3.0-liters), while the SL stands for Sport Leicht, which is German for Sport Light. Originally offered as a coupe, the 300SL was the first of the SL-Class grand tourer models, and eventually, it morphed into an open-top roadster. Although it lost the highly recognizable gullwing doors, the 300SL Roadster managed to keep much of the speed and prestige of its predecessor, all while adding on-demand blue-sky freedom.

These days, Mercedes pays homage to its past with a variety performance models which recall the 300SL’s styling and sporty character, and while the speed and technology are there, none can match the style and grace of the original.

Continue reading to learn more about the 1957 Mercedes 300SL Roadster.

  • 1957 Mercedes 300SL Roadster
  • Year:
    1957
  • Make:
  • Model:
  • 0-60 time:
    7.1 sec.
  • Top Speed:
    150 mph
  • car segment:

History And Background

1957 Mercedes 300SL Roadster High Resolution Exterior
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The genesis of the 300SL Roadster starts in early ‘50s America, at the peak of the postwar economic boom. Max Hoffman, an Austrian-born, European luxury car importer based out of New York, saw an opportunity to sell high-performance, race-inspired sports cars to well-off speed aficionados in the U.S., and subsequently pitched the idea to Mercedes. It was a risky proposition, but the German automaker decided to follow through, and in 1954, the production-ready 300SL Coupe debuted at the New York Auto Show.

Essentially a luxury-laden, street-worthy race car, the 300SL was based on the 1952 Mercedes-Benz W194, a highly successful grand prix car that saw victory at the 24 Hours of Le Mans, Nurburgring, and Carrera Panamerica, with drivers like Juan Manuel Fangio and Stirling Moss taking the position behind the wheel. Incredibly, power was increased substantially in the 300SL compared to the competition-spec vehicle, making it the fastest production car in the world at the time.

The car was an instant hit. Wealthy celebrities clamored to own one, catapulting Mercedes to the forefront of luxury sports cars in the U.S. In total, 1,400 were built.

In 1957, Hoffman once again approached Mercedes, this time with a proposal to turn the Coupe into a convertible. Mercedes wisely listened, and in 1957, the 300SL Roadster debuted at the Geneva Motor Show. While not quite as wild as the gullwinged Coupe, the Roadster was equally as popular, with 1,858 examples built until production ceased in 1963.

Exterior

1957 Mercedes 300SL Roadster High Resolution Exterior
- image 672901
1957 Mercedes 300SL Roadster High Resolution Exterior
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1957 Mercedes 300SL Roadster High Resolution Exterior
- image 674265

The 300SL takes its design cues and exterior aesthetic from the W194. Standout features include an extended hood, rear-set cockpit, rounded frontend, and raised taillights and fenders.

When Mercedes introduced the 300SL Roadster, the exterior closely mimicked that of the Coupe, with a few notable exceptions.

The 300SL, however, builds on the W194’s ultra-sleek and uncluttered appearance with far more embellishment. Chrome is used front to back, including in the bumpers, window surrounds, and accents, and a prominent louvered cutout is placed just behind the front wheel. Above the wheel arches, you’ll find long extensions, or “eyebrows,” which were supposedly added to enhance aerodynamics (although some have suggested their implementation was to help the 300SL appeal to U.S. customers accustomed to flashier designs).

When Mercedes introduced the 300SL Roadster, the exterior closely mimicked that of the Coupe, with a few notable exceptions. Most obvious were the conventional doors, which no longer had a roof to hinge on. The fenders were enlarged, as were the headlights. The windshield was also reshaped, and the front grille shrunk. The sills were made much lower, significantly aiding ingress and egress compared to the Coupe. Finally, customers got a ragtop as standard, while an installable hardtop was offered for the offseason.

Exterior Dimensions

Track (front/rear) 1,398 MM (55 in)/ 1,448 mm (57 in)
Wheelbase 2,400 MM (94.5 in)
Length 4,570 MM (179.9 in)
Width 1,790 MM (70.5 in)
Height 1,300 MM (51.2 in)

Interior

1957 Mercedes 300SL Roadster High Resolution Interior
- image 674273

One feature unique to the Coupe was its foldaway steering wheel, which wasn’t needed with the conventional doors and lowered sill of the Roadster. Funny enough, the Roadster is more practical when it comes to cargo, as it got a redesigned fuel tank that moved the spare wheel lower, freeing up space in the trunk.

The cockpit is tight, and not just because of limited cabin room. The seats hug both the driver and passenger with rigid lateral bolsters. That said, every surface is covered in premium materials. A brushed-metal panel houses all the requisite buttons and knobs, while behind the steering wheel, you’ll find dual gauges for engine revs and speed. The Roadster also added a combination gauge between the tachometer and speedometer. A rearview mirror is mounted on top of the dash.

Drivetrain

1957 Mercedes 300SL Roadster High Resolution Interior
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The 300SL uses a front-engine, RWD layout. Tucked into the nose is a four-stroke, water-cooled, SOHC 3.0-liter straight six-cylinder. It’s the same engine used in the grand prix cars and four-door Mercedes-Benz Type 300, but compared to those vehicles, the 300SL was significantly more powerful.

Output was rated at 212 horsepower at 5,800 rpm, and 202 pound-feet of torque at 4,600 rpm – both highly impressive numbers for the time.

Output was rated at 212 horsepower at 5,800 rpm, and 202 pound-feet of torque at 4,600 rpm – both highly impressive numbers for the time. In fact, the 300SL made 25 percent more power than the race cars, not to mention nearly double the horsepower of the Type 300. Routed to the back of the lightweight two-door, the car’s top speed approached 160 mph, making the 300SL the fastest production car on Earth when it was new.

Making all the extra muscle is a revolutionary Bosch mechanical fuel injection system, which replaced the triple two-barrel carbs on the original powerplant to become the first fuel injection system used on a production street car. Interestingly, the system was first developed on the Messerschmitt Bf 109E fighter plane that flew in World War II.

While technologically astounding, the fuel injection system was also known for wrecking havoc on the 300SL’s engine. Unlike modern electric fuel injection systems, the mechanical system on the 300SL would continue to inject fuel even after the ignition had been switched off, effectively washing the cylinder walls. This resulted in sections of the engine being left unprotected at start-up and the dilution of the oil.

Several factors exacerbated the problem. For example, if the car wasn’t driven hard, the oil never got hot enough to evaporate the fuel, a problem made worse by the oversized racing oil cooler and 10-liter oil capacity. To help remedy the issue, Mercedes recommended changing the oil in short 1,000-mile intervals. Additionally, some owners found a fix by blocking airflow to the oil cooler to make sure it got hot enough during operation.

The engine uses a diagonal aluminum head for enlarged intake and exhaust valves, and the whole thing was tilted forty-five degrees so it could fit under the 300SL’s low hoodline. In 1962, Mercedes introduced an aluminum block.

Sending the power aft is a four-speed manual gearbox. The Roadster was offered with a 3.64:1 axle ratio as standard, but was also available with 3.25:1, 3.42:1, 3.89:1, or 4.11:1

Chassis And Handling

1957 Mercedes 300SL Roadster High Resolution Interior
- image 672907

The 300SL was made mostly from steel, but it did incorporate a fair amount of aluminum as well. The chassis is a steel tube space frame. The car’s dry weight is 3,130 pounds, while throwing on the optional hard top adds another 88 pounds. The Roadster is heavier than the Coupe, as the convertible needed additional bracing to help it maintain adequate structural rigidity without a roof. Diagonal struts were added to buttress the lowered side sections and rear tubular members, and the result is about 250 pounds of extra heft.

Despite the weight, the Roadster is seen as the better car to drive.

Despite the weight, the Roadster is seen as the better car to drive. Both the Roadster and Coupe came with four-wheel independent suspension, with double wishbones, coil springs, and a stabilizer bar in the front. In back, however, the Coupe’s dual-joint, high-pivot rear swing axle was replaced with a low-pivot swing axle and transverse compensating spring on the Roadster, which offered greater predictability at high speeds and over rough roads.

Because the Coupe’s enormous 34.3-gallon gas tank could affect the car’s handling depending on how much fuel was onboard, the Roadster downgraded to a smaller (but still sizable) 26.4-gallon tank.

The Roadster used grippy, power-assisted drum brakes, measuring in at 260 mm (10.2 inches) in diameter. In March of 1961, Mercedes introduced new power-assisted disc brakes, which were measured at 290 mm (11.4 inches) front and rear.

Prices

When new, the 300SL Roadster sold for $10,928 – a substantial chunk of change for the ‘50s.

Nowadays, the 300SL is considered one of the most desirable Mercedes models of all time. Well-preserved examples hit the auction block for around a million dollars, while the more rare models (celebrity ownership, exclusive options, etc.) go for much, much higher.

Competition

Jaguar XKSS

1969 Lynx-Jaguar XKSS High Resolution Exterior
- image 637677

After Jaguar withdrew from competition at Le Mans in 1957, it had a handful of surplus D-Type race cars lying around with nothing to do, so plans were drawn up to convert the competition-spec vehicles into high-performance street cars. Jag made simple modifications in the transformation, adding a foldable soft-top, a larger windshield, and a door for the passenger, while also removing the large fin behind the driver. The car was still wickedly fast, with a cutting-edge inline six-cylinder that offered enough output to push the XKSS to a very quick 150-mph top speed. The car is also incredibly rare, fetching millions at auction.

Read the full review here.

Ferrari 250 GT California SWB Spider

1961 Ferrari 250 GT SWB California Spider by Scaglietti Exterior
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When talking about classic European sports cars, you gotta at least mention the Ferrari 250. Built between 1953 and 1964, the Prancing Horse made a multiplicity of model types, including both street cars and race cars. Designed specifically for the west coast sunshine, the 250 GT California got a shorter wheelbase, disc brakes, and a 3.0-liter V-12 engine that made enough power to push the car all the way to 140 mph. Only 55 were built, and some recent auctions have seen prices reach as high as $17 million.

Read the full review here.

Conclusion

1957 Mercedes 300SL Roadster High Resolution Exterior
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Six decades later, Mercedes is still telling the legend of the 300SL. We see it in models like the SLS AMG, which offers a modern take on the classic, coming equipped with the latest high-end technology, similar styling cues, and gratuitous speed, both as a hardtop and a soft-top.

Frankly, Mercedes has every right to be proud. It takes hutzpah to turn a race car into a street car and hope people buy it. And even with the supercar formula now well established, and the go-fast breed accelerating into even crazier realms of velocity, we can still look to the original to see how it’s supposed to be done.

  • Leave it
    • Absurdly expensive and rare
    • Fuel injection system could ruin the engine
    • Not the Coupe
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