Mercedes-Benz restores oldest SL to mark 60th anniversary

This year marks the 60th anniversary of the Mercedes-Benz SL and to celebrate the occasion, Mercedes has completely restored the oldest surviving example to its original condition. The restored car's unveiling coincides with the introduction of latest versions of the SL for 2013: The SL 500 and the SL 350.

The original SL

By 1951, Mercedes-Benz had resumed post-war production for five years and was keen to get back into the racing circuit that had done so much for the company's public image before the war. On 12 March 1952, on the autobahn between Stuttgart and Heilbronn, Mercedes-Benz introduced its sports car prototype to the press: The 300 SL. With a 94.5-inch (240 cm) wheelbase and an overall length of 166-inches (423 cm), the 300 SL was designed to weigh as little as possible. "SL" stands for "Super Lightweight" and to achieve this, Mercedes built the car around a tubular steel frame that looked less like a car chassis than it did one of Buckminster Fuller's nightmares, but it weighed only 110 lbs (50 kg). Further weight savings came from using aluminum body panels and aluminum and magnesium components where possible. This kept the overall weight down to 2,300 lbs (1060 kg).

The car was powered by a 3-liter, six-cylinder in-line engine canted at 50 degrees with an overhead camshaft, three Solex twin carburetors and dry sump lubrication, which put out 170 bhp for a maximum speed of 143 mph (230 kph). Not bad for 1952.

But what most people noticed first thing about the SL was the doors. They didn't swing out like conventional car doors. They swung up. Soon dubbed "gullwings" these were not the result of some car designer's fancy. They were, in fact, the answer to a problem that kept cropping up in the car design: How do you get into the blasted thing? The brilliant tubular steel frame may have cut down the weight, but it didn't leave any room for a door. So, the engineers put in a sort of access hatch for the driver that evolved into a proper, and very cool-looking door that swung up instead of out.

Racing stripes and a production model

The 300 SL did very well on the racing circuit It came in second and fourth in the Mille Miglia, claimed a threefold victory in the "Prix de Berne" sports car race, a double victory in the 24 Hours of Le Mans, won four times in the Nürburgring Anniversary Sports Car Grand Prix and twice in the 3rd Carrera Panamericana in Mexico. That would have been the end of the SL, which saw only ten built, but interest from the United States to the tune of a thousand orders prompted Mercedes to put the sports car into production. The company sent it back to the shop, tinkered with the design to make it a bit more civilized with little things like air vents, chrome grills and even cooler gullwing doors, then unveiled it to the public as the 300 SL production model at the New York Auto Show in 1954.

Fast forward to 2012 and Mercedes-Benz is celebrating the 60th anniversary of the SL marque. As part of this, the company decided to restore the oldest surviving SL, which has remained in company ownership. Sadly, the first 300 SL was scrapped long ago, but the second, chassis number 194 010 00002/52 carries on. Restoration took some doing because the aluminum/magnesium body sheets are very delicate and are very difficult to work with as they age. The entire car had to be dismantled and each part cleaned and restored in a meticulous ten-month process. The body shell alone took six months. But in the end, the result was as close to original condition as possible with the 300 SL restored to not only aesthetic beauty, but running condition.

This restoration is particular important to Mercedes-Benz because it wanted to have the 300 SL ready to stand by the latest versions of the SL as they were unveiled to the public: The SL 500 and the SL 350.

A new generation

Over the years, the SL has evolved considerably. It started out as a racing car, morphed into a sports car in the mid-1950s, then became a small luxury coupé and convertible in the Sixties. Today the roadster version is filled with all the mod cons from air conditioned seats to hard tops that fold down in less than 20 seconds. The 2013 Mercedes-Benz SL roadsters have an all-aluminum body, a new bi-turbo engine and Internet connectivity. Called a "6th Generation" car by Mercedes-Benz, the new SL class emphasizes a combination of lighter weight with greater horsepower for improved performance and fuel efficiency.

The Mercedes-Benz SL class has been a car to watch ever since its introduction in 1952. It's famous "gullwing" version introduced in 1955 is one of the world's most collectible cars (one recently sold at auction for US$4.6 million) and the lightweight sports car was the first to employ direct fuel injection. For the latest model, Mercedes-Benz has redesigned the car for lighter weight, greater performance and a tweaking of its luxury features to include full internet access.

The centerpiece of the 2013 SL is its BlueDIRECT engine. Available in both a 3.5-litre V6 for the SL 350 and 4.6-litre V8 configuration for the SL 500, the BlueDIRECT engine is built around an aluminum engine block and uses third-generation spray-guided direct petrol injection and ECO start/stop function to improve fuel performance by up to 24 percent to providing up to 35 mpg. Two turbochargers increase the torque to 273 lb-ft (370 Nm) for the V6 and 516 lb-ft (700 Nm) for the V8, giving the SL 350 306 bhp to play with and the SL 500 a blistering 429 bhp. Pressing the accelerator shoots the SL from 0 to 60 mph (100 kph) in 4.5 seconds.

Aluminum body shell

This new SL features the first all-aluminum body shell that Mercedes-Benz has used in a production car and allows its designers to shave 243 lbs (110 kg) off the car's weight. "The effect is rather as if a heavyweight-class passenger had got out of the car," says Dr Thomas Rudlaff, who was responsible for the aluminum body shell.The company says that the new body provides greater rigidity, safety and comfort than the older steel version. This use of aluminum was carried throughout the SL - even the steering knuckles and spring links on the front axle are aluminum. In all, the weight of the SL 500 comes in a under 4,000 lbs (1,800 kg) and the SL 350 at 3,700 lbs (1,680 kg). That's impressive for a car where in the 1960s versions the paint alone weighed 45 lbs (22 kg).

The interior of the SL has been redesigned for more space and the fold-down hard top is equipped with "Magic Sky Control", a feature that allows the driver to press a button and change the glass panel in the roof from dark to transparent. Folding down the roof activates a pop-up wind baffle behind the passenger seats, which should save the odd scarf or toupee from ending up in the road.

One optional extra for the new SL is COMAND, the COckpit Management And Data system. With this, the driver not only has full Bluetooth telephony, but when the car in stationary, it has complete access to the Internet and high-speed access to Mercedes-Benz services, such as weather reports or destination searches.

As part of its 2013 roll out Mercedes-Benz is offering for a limited "Edition 1" version of the SL equipped with a panoramic vario-roof, AMG bodystyling, sports suspension, AMG 19-inch light-alloy wheels, nappa leather with contrasting top stitching, heated seats, ambient lighting and a Harman/Kardon Logic7 surround sound system.

Quite a jump from the early days of the SL.

The new SL 350 is priced at EUR93,534 and the SL 500 costs 117,096.00 euros - add around EUR20,000 for the Edition 1 package.