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2009 Mercedes SLR McLaren 722 S: Like Son, Like Father

When Mercedes puts the SLR name on a car, it’s like walking on hallowed ground. A name borne from a conviction to speed, innovation, and courage. SLR, meaning Super Light Racer, is a label that Mercedes respects more than any other moniker they use today. A signature so sacred to the Daimler group that, in the ninety years of their existence, they’ve only used it twice. To see why it’s so special, we need to look in the past.

Juan Manuel Fangio in the 300 SLR at the Mille Miglia

It started with this: the 1955 Mercedes-Benz W 196 S (Sport) also known as the Silver Arrow and also known as the 300 SLR. It was developed in parallel with the W 196 R (Racing) which was used in Formula 1 and featured its own open wheel or long wheelbase variations. Both versions were a continuation of the W 196 race car that had won numerous accolades so far.

Between the two them there were a surprising amount of relatively space-aged technologies. Both had a welded tube frame chassis, direct injection, and desmodromic valve control. The 300 SLR had its own special treatment as it was purpose built for endurance races. Unlike the W 196 R that had a 2.5-liter engine, this one used a 3.0-liter straight-8 for more power and torque. As a result, the 300 SLR was capable of generating 302 to 310 hp at 7,500 rpm for a top speed in excess of 186 mph (300 kmh). A speed that’s disturbingly quick for a car with inboard drum brakes, swing axle suspension, and a rear mounted transmission (sitting past the rear differential). At least there was a manually operated air brake in the back to help slow things down.

Juan Manuel Fangio and Stirling Moss - Mercedes top racing drivers - utilized the 300 SLR to its maximum potential at the Swedish Grand Prix, Targa Florio, and Nürburgring for multiple podium finishes. If Fangio won first place, Moss took second. If Moss took first, Fangio was right behind. Both drivers, combined with the powerful 300 SLR gave Mercedes an untouchable status on the track. Their season was so great, they were starting to embarrass Ferrari..

One of their most famous podium finishes was at the Mille Miglia - a 992 mile (1597 km) race set in the Italian countryside. The route from Brescia to Rome and back was a grueling test of mechanical fortitude, bravery, and a reckless disregard for human lives. Here, Stirling Moss teamed with Denis Jenkinson as co-driver for notes and directions in car number 722. And according to Jenkinson and bystanders, Moss’s driving could best be described as ferocious - jumping in the air for 50 ft (15m) on a crest, doing a 360 degree spin after hitting oil, and driving flat out through hay bales as a shortcut throughout the race. In the end, his 10 hour 7 minute lap time meant an average speed of 97 mph (157 kmh). A record that hasn’t been beaten since.

The momentum of their victories came to a grinding halt after an incident at the 1955 Le Mans race. One that cost the lives of drivers and spectators alike causing Mercedes to withdraw from future motorsport events. Afterwards, officials took to redesigning the track and regulations for safety while Mercedes started paying more attention to their road cars. Still, the message was clear. Between Mercedes, the 300 SLR, and its drivers, they were the best in the world.

48 years later the SLR returned as a supercar. But in order to attempt to follow the closet full of trophies the Mercedes forefathers left behind, the new team of engineers would have to employ the help of their partially owned McLaren partners. So, similar to the F1 development team, Mercedes supplied their AMG engines and interior details while McLaren handled the chassis, suspension, and driveline mechanics. Ultimately, the SLR was assembled in a McLaren factory in Woking, England following Mercedes specifications.

The resulting collaborative design is one that’s both stunning and respectful of the cars that preceded it. The shape of the front nose, for example, is an homage to the Silver Arrow name. On the sides, vertical louvers and side exit exhausts give the SLR a 1950s flair with a modern twist. Gullwing doors were inspired by the 1954 300 SL Gullwing - the first car to have direct injection thanks to the developments from the W 196. And in the back, an active aero brake rises up for face tearing amounts of stopping power.

What sets the Mercedes SLR McLaren apart from the Porsche Carrera GTs and Ferrari Enzos of this era was its commitment to being the ultimate long-range cruise missile like the 300 SLR. It had to be comfortable, controllable, robust, easy to use, and of course - fast. That’s why its engine sits in the front-middle and only comes equipped with a 5-speed automated-manual gearbox. A rear mid-engined build would be too much of a handful for spirited driving sessions.

And when it comes to power, it’s easy to see why they would put it in the front. Sitting just behind the front axle is a hand built SOHC 5.4-liter twin screw supercharged AMG V-8. Its M155 SLR dry sumped engine produced 617 horsepower and 575 lb-ft of torque giving the new silver arrow a 0-60 time of 3.8 seconds, a completion of the quarter mile in 11 seconds, and a top speed of 206 mph (331 kph). Coincidentally, the M155 has the same 9:1 compression ratio as the 300 SLR though it probably wasn’t intentional.

McLaren’s contribution consisted of its pure carbon fiber chassis, forged-aluminum SLA suspension, and hydraulically powered 8-piston and 4-piston caliper brakes squeezing on carbon ceramic discs. Grip came from Michelin Pilot Sport 2 255/35 R19 and 295/30 R19 tires that was the prime choice for cars of this caliber.

Later on, in 2006, Mercedes released a 722 edition of the SLR. The tributary model consisted of lighter wheels, a newly redesigned aerodynamic front end, and an engine tune that pumped the 5.4-liter V-8 up to 641 horsepower. The subsequent upgrades dropped the SLR McLaren’s 0-60 to 3.6 seconds while upping the top speed to 208 mph (334 kph). One year after, Mercedes released a roadster for all versions of the SLR McLaren. Finally, in 2009, Mercedes came out with their last road-going SLR called the 722 S featuring special paint and a 10 mm suspension drop. Only 24 722 S models were built for the U.S. making them especially rare by supercar standards.

Behind the wheel, the SLR handles easier than you’d expect for a monstrous rear-wheel-drive supercar. Its six different driving modes and smooth power band make cross country efforts… effortless, though Mercedes doesn’t allow you to fully turn off its electronic stability control for fear of letting the driver have too much fun. Nevertheless, its near 50/50 weight distribution astonished reviewers with its resilience to understeer. Special edition and roadster versions were said to perform in a similar fashion. Inside, a 7-speaker Bose sound system and a collection of high quality trims contribute to the luxury experience. If you were fortunate enough to order one when they first came out, Mercedes even offered to tailor the leather/Alcantara seat with cushions to fit your body.

Now the question is: Did it live up to its name? Not quite. For a supercar in its price and pedigree, it’s not exactly super light and it isn’t much of a racer. A lot of its key features didn’t bring as much to the table as the 300 SLR. Carbon fiber body, active aerodynamics, gullwing doors, carbon ceramic brakes… they’ve all been done before. And few enthusiasts would hypothetically choose the SLR McLaren over the Porsche Carrera GT or Ferrari Enzo. That should explain why its recent performance in auctions barely exceeds its original sticker of half a million dollars. It failed to forge a new level of prestige for Mercedes.

But it did serve a different purpose. During the seven years of the SLR production, McLaren was slowly gaining experience and expertise in how to build supercars on a slightly larger scale - eventually giving them the drive to initiate their own venture. After the Mercedes SLR McLaren ended its run in 2010, McLaren released a fully bespoke supercar called the MP4-12C. Its ensuing success led to the P1, 650S, 675LT, and 570S - establishing creative new approaches to aerodynamics and chassis design. Each one a shining example of the spirit of the Super Light Racer.

All photos by Drew Shipley ©2016 Courtesy of RM Sotheby's