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Mercedes also will show a CLK premium roadster with a hybrid powertrain that includes an integrated starter-generator.

MUNICH -- Mercedes-Benz will show a diesel-electric hybrid version of its new S-class upper-premium sedan at the Frankfurt auto show in September.

The world’s fastest open-top four-seater

High technology derived from motorsport, the handling dynamism of the racetrack, a sensational visual appearance and the utmost exclusivity – the new Mercedes-Benz CLK DTM AMG Cabriolet is guaranteed to make the hearts of true car lovers beat faster. A limited edition of 100, the CLK DTM AMG Cabriolet is capable of a fulminating performance with its 428-kW/582-hp AMG 5.5-litre, supercharged V8, a newly developed AMG sports suspension, optional sports tyres and aerodynamics refined in the wind tunnel: this high-performance AMG sports car accelerates to 100 km/h in just 4.0 seconds and has a maximum speed of 300 km/h (electronically limited). This makes the new high-performance AMG Cabriolet the world’s fastest open-top four-seater.

The great demand for the CLK DTM AMG Coupé, which was likewise a limited edition of 100 and rapidly sold out, provided the initial impetus for the development of the powerful high-performance AMG Cabriolet. It was also modelled on the most successful car in the German Touring Car Masters – the racing version of the Mercedes-Benz CLK with which Bernd Schneider was able to win the DTM championship in the 2003 season. The equipment of the CLK DTM AMG Cabriolet also takes its lead from the racetrack: AMG sports bucket seats with leather/Alcantara upholstery guarantee optimal lateral support, while the buckskin-covered, oval AMG racing steering wheel and the AMG instrument cluster with its 360 km/h speedometer scale lend an unmistakable motorsport touch to the interior.

The exterior design of the new CLK DTM AMG already suggests outstanding performance at the level of thoroughbred sports cars, and demonstrates the transfer of top-class technology from the world of motor racing: a deep-drawn front apron with large air inlets, prominently flared wheel arches, 19 and 20-inch AMG light-alloy wheels and the diffuser-look rear end with its aerofoil are reminiscent of the successful CLK racing tourers from the DTM. Numerous body components are made from particularly strong and lightweight carbon fibre reinforced plastic (CRP), for example the bonnet, doors, front wings, flared rear wheel arches and aerofoil.

Performance at the level of a super sports car

The Cabriolet is powered by the supercharged AMG eight-cylinder engine, which is familiar from other AMG cars but has been specifically reengineered with modifications to the crankcase, pistons, valve gear, cooling, intake manifold, supercharger and exhaust system. The AMG V8 engine generates a maximum output of 428 kW/582 hp at 6100 rpm from a displacement of 5439 cubic centimetres, while the maximum torque of 800 Newton metres is available at 3500 rpm.

Instant response to movements of the accelerator, a powerful surge of torque, exhilarating liveliness and an unmistakable V8 sound are the particular strengths of this ultra-powerful, supercharged AMG 5.5-litre V8 unit, which gives the new CLK DTM AMG Cabriolet the sort of performance levels found in super sports cars. the 100 km/h mark is reached from standstill in just 4.0 seconds, and the top speed is 300 km/h (electronically limited) – no other open-top four-seater in regular production can match these figures. A racing touch is also provided by the AMG SPEEDSHIFT five-speed automatic transmission: the five gears are changed by briefly pulling the shift paddles on the steering wheel, with extremely short shift times guaranteeing a particularly sporty and direct driving experience.

Newly developed torsion suspension, limited-slip differential

The suspension is fully the equal of the high-performance engine. In line with usual motor racing practice, a height-adjustable torsion suspension system is used. The rear axle has been redesigned with completely new spring links and wheel carriers, as well as reinforced drive shafts. The usual rubber elements are replaced by uni-ball joints on both axles to produce outstandingly precise handling. A multi-disc limited slip differential on the rear axle ensures optimal traction, while acceleration skid control (ASR) and the Electronic Stability Program ESP® have been adapted to suit the increased performance potential.

Optional Dunlop sports tyres for particularly good grip

Outstanding road contact is provided by the optional sports tyres by the DTM motorsport partner Dunlop; these size 225/35 R 19 (front) and 285/30 R 20 (rear). These tyres have particularly good grip and are fitted to multi-piece 9 x 19 and 10 x 20-inch AMG twin-spoke light-alloy wheels. These elegant spokes are not only an eye-catching feature, but also ensure effective ventilation of the brakes. Superb deceleration is provided by the newly developed AMG high-performance composite braking system with six-piston fixed callipers at the front and four-piston fixed callipers at the rear.

Functional racing atmosphere in the interior

The interior of the CLK DTM AMG is characterised by a functional motor racing atmosphere, with a judicious touch of the exclusivity expected of a genuine AMG high-performance car. AMG sports bucket seats of ultra-light CRP with leather/ Alcantara upholstery provide the occupants with outstanding lateral support, while the AMG sports steering wheel with its oval rim is covered in high-grip buckskin and gives the driver an excellent feel for the vehicle. Like the instrument cluster, the door linings and other interior components are of lightweight CRP. The silver-coloured shift gate, starter button and four rocker switches are eye-catching features on the redesigned centre console.

Despite a performance potential worthy of the racetrack, the CLK DTM AMG has all the virtues typical of any Mercedes model: everyday suitability, durability, safety, quality and standards of service to satisfy even the most demanding requirements. The fast AMG Coupé is hand-assembled in close cooperation between Mercedes-AMG GmbH and H.W.A. GmbH. The latter is one of the most successful touring car racing teams, and is also responsible for assembly and operation of the current C-Class DTM cars. The first of the limited-edition CLK DTM AMG Cabriolets will be delivered to customers during the first half of 2006. Mercedes-AMG GmbH is responsible for marketing, sales and service.

CLK 63 AMG to Debut at Geneva

The CLK 63 AMG Coupe and Cabriolet models are ready for their world debut in Geneva. The CLK 63 AMG produces more power and torque – 481 bhp and 465 lb-ft – than any other vehicle in this class. The new AMG SPEEDSHIFT 7G-TRONIC transmission complements it perfectly, helping to ensure dynamic power delivery.

The new AMG sports suspension, new 18-inch AMG light-alloy wheels and luxurious and dynamic standard appointments add to the exclusive and sporty theme of the CLK family. In addition, the front wheels are equipped with a new AMG high-performance composite brake system.

The dynamic AMG bodystyling, featuring a new, more distinctively contoured front apron with side air vents, underscores the CLK 63 AMG's position as a sporty flagship model combining dynamism with exclusiveness. These qualities are also on display in the interior, for example in the new AMG ergonomic sports steering wheel, multicontour AMG sports seats and exclusive nappa leather upholstery.

Mercedes-Benz CLK63 AMG
The CLK63 AMG replaces the CLK55 AMG. The CLK gets AMG’s new naturally aspirated, 6.2-liter, V-8 engine that debuted last summer. The powerplant is the first engine developed by AMG that is not based on any Mercedes engine.

Sometimes it’s hard to tell which is the cart and which is the horse. Sometimes, in automobiles, it doesn’t matter which goes first. There is engineering (product) and there is marketing (hype), and now there is a new showpiece V8 from AMG. It’s called the 6.3.

The 6.3 stirs emotion on at least two levels. For the foreseeable future, this engine will power most of the hot rod Mercedes crafted by the firm’s high-performance subsidiary. It generates wads of horsepower and torque—nearly 500 units of both—and it’s more refined at the extreme edge of its performance envelope than the tweaked Mercedes V8s it replaces. Figuratively, the new 6.3 connects AMG with its glorious past and the mother company’s past. Its name is symbolic, even if the symbolism follows a slightly convoluted path back to the 1960s.

The designation 6.3 is rich with heritage at Mercedes-Benz. To aficionados, it represents a car more than an engine—one of the finest cars in Mercedes’ post-World War II stable. The original 6.3-liter V8 debuted in 1962 in the new M-B 600 uber-sedan, which was to the mid-’60s as the Maybach 57 is to 2006. Known internally as the M-100, the first 6.3 V8 was a he-man among boys, with engineering decades ahead of the curve. It featured fuel injection, aluminum cylinder heads, overhead camshafts and sodium-filled valves, with forged pistons, rods and crank. Each hand-built copy was bench-tested for 265 hours, 40 of which were consecutive at full load.

In 1966 a roguish Mercedes engineer named Erich Waxen-berger hatched a plan, and he intended to implement it whether the tri-star went along or not. As a private venture, Waxenberger installed an M-100 in Mercedes’ 300 SEL—the company’s standard full-size six-cylinder sedan (codename W-109, or six generations of S-Class past). Darned if the powers in Stuttgart didn’t like what Waxenberger had wrought. In 1968 Mercedes introduced the 300 SEL 6.3. The 6.3, as it was known, continued in production through 1972 and laid the groundwork for the subsequent M-100-powered 450 SEL 6.9.



The 6.3 was Europe’s muscle car, arguably the first super sedan and progenitor of all the AMG, M and RS cars that followed. Its performance shamed dedicated sports cars like the Porsche 911, and its air suspension allowed impressive handling and stability. The M-100 V8 generated 300 hp and 436 lb-ft of torque; matched with a four-speed automatic, it propelled the 6.3 to 60 mph in 6.2 seconds. The 6.3 could cruise all day at 140 mph, with four of its five occupants licking ice cream cones as they enjoyed music from the Becker stereo.

Coincidentally, AMG was formed the same year Mercedes launched the 300 SEL 6.3. In the early days this prototypical tuning firm was just that—a tuner kept at arm’s length by the mother company, known only to a relative handful of performance nuts. Yet by 1971 AMG had planted itself indelibly in the automotive landscape. That year it prepared a 300 SEL 6.3 that went from nowhere to a class victory at the 24 Hours of Spa, finishing second overall. To be sure, AMG’s race car wasn’t really a 6.3. Its M-100 was punched out to 6.8 liters.

Fast forward 35 years. AMG has been a wholly owned subsidiary of DaimlerChrysler since 1999, and a new 6.3 V8 is its first engine designed and developed entirely in-house. Its block (bore centers) is different from that used for the new four-valve, 5.5-liter Mercedes V8 introduced in the 2006 S-Class. AMG’s 6.3 was created for “higher specific output and specific torque than any other series-produced naturally aspirated eight-cylinder engine in the world,” according to the company, with “20 percent more torque than comparable naturally aspirated engines with a similar power rating.”

Whether or not AMG’s claims are accurate, the new V8’s nomenclature technically is not. It is barely a 6.2, displacing 6208 cc. The “6.3” nonetheless features high-tech parts and materials you would expect from Mercedes’ captive tuner, and some things you might not expect. The intake and exhaust ports are vertical, to maximize airflow velocity, and the valvetrain is stiffened with features like bucket tappets to support smooth operation at the 7200-rpm redline. The main bearing caps are not caps at all, but a fully boxed lower crankcase section that virtually eliminates crank flex. There are no bore liners in the aluminum block. The cylinders are coated with a micro-thin, electrostatically applied ceramic/metallic material and then machined.


AMG’s V8 has dry-sump lubrication, like the original 6.3, but it also applies technology that engineers developing the M-100 probably could not have imagined, including four-cam phasing and a variable intake system with two integral throttle flaps.

The most important stuff? Horsepower will vary as much as 40 in various 6.3s, depending on vehicle configuration—and the amount of air AMG can move through its new V8. Yet in all cases, it’s impressive: 475 hp at 6800 rpm in the forthcoming CLK63, 503 hp in the ML63 and RL63, and 514 hp in the CLS63. In each, the 6.3 V8 generates more horsepower than AMG-tweaked variants of the three-valve Mercedes V8 that previously powered these cars, supercharged or not. That said, the 6.3 generates less torque than the previous supercharged 5.5: 465 lb-ft compared to 516 lb-ft.

AMG cars built with the 6.3 will be the first to use Mercedes’ seven-speed automatic transmission, labeled the AMG Speedshift 7G-Tronic. Massaged to handle mega torque and improve response, this ransmission reduces shift time 50 percent in manual mode, compared to the standard Mercedes version, according to AMG. The AMG 6.3s will also come standard with new composite brake rotors and a feature called Racetimer. Similar to Porsche’s Sports Chrono option, Racetimer records acceleration, top speed or lap times and stores them for retrieval at the driver’s request.

In the CLK63 AMG, the new V8 is a welcome improvement. Previously powered by the naturally aspirated 5.5, this car was merely fast. With the 6.3 and seven-speed, it’s blindingly quick. Throttle response is instantaneous, automatic downshifts nearly so, and the manual-control electronics are better programmed to hold a gear near the redline. This is one of the most impressive powertrain combinations from Mercedes in years—smoother at high revs than the previous AMG engines. There’s a nice burble at part throttle, and something more like a banshee scream when you floor it.


The CLK was already one of the most driveable cars in AMG’s inventory; with the 6.3 it’s more so. No Active Body Control here—just good suspension tuning, decent steering feel and crisp turn-in. Some Mercedes-Benzes will dutifully go along for the ride when pushed, behaving quite predictably all the while. The CLK63 relishes a kick in its flanks. Of course, we sampled the 6.3 in a CLK coupe, and coupe people on this side of the Atlantic won’t get the same opportunity. Mercedes will send only the CLK63 cabriolet to North America.

We also tried the forthcoming ML63 AMG, and the package certainly has its appeal: a people hauler to engage 911s in the stoplight derby or blast through big sweepers much faster than decorum or good sense might suggest. Yet through the twisties where we sampled it, changing directions quickly and often, the ML63 is not exactly fun. Its massive tires mean plenty of grip. The steering is fairly quick for such a hefty machine, but also quite light, and the package conspires to feel twitchy—almost unsettling.

The AMG 6.3s will reach the United States as 2007 models. The CLK cabrio arrives in July (expect a substantial price increase over the existing model’s $83,275) and the ML in August, with the CLS and R-Class (there’s an interesting concept) some time after that. Buyers will no doubt be waiting.

Mercedes sold nearly 20,000 AMG cars in calendar year 2005—more than the entire run of M-100-powered cars over that engine’s 19-year production span. One technician assembles each AMG engine, start to finish, so the crew in Affalterbach is clearly busy.

The 6.3 is the new cornerstone of AMG’s identity. Director Wolf Zimmerman says AMG needs an engine all its own, despite what those 20,000 sales might suggest. In 10 or 15 years we’ll begin to know whether history judges the new 6.3 as reverently as the M-100 V8.


In 2006 the 6.3 is impressive, if not incredible. The 7.0-liter LS7 Corvette V8 generates similar power (505 hp, 470 lb-ft, 7100-rpm redline), with one fixed-timing cam and pushrods. Zimmerman says there is probably 50 more horsepower in the AMG 6.3, if AMG can figure out how to eliminate intake or exhaust flow restrictions in the various vehicles. If the market demands substantially more, it’s back to a blower of some sort.

Mercedes has a remarkable history of supercharging, by the way, dating all the way back to the early 1900s.