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Mercedes-Benz is unveiling a fourth member of its iconic SL sports car family – the SL63 AMG. Perhaps the sportiest SL roadster ever, the new SL63 AMG is powered by a 6.3-liter, all-AMG V8 engine that’s coupled to a newly developed MCT transmission.

Featuring an innovative start-up clutch that replaces a conventional torque converter, the seven-speed MCT (for multi-clutch technology) transmission combines the direct connection of a manual gearbox with the lightning-quick automatic gear shifts of a Formula 1 race car. Topping off the SL chassis is an even more agile AMG sports suspension based on the Mercedes-Benz ABC active suspension.


Providing the direct feedback of a manual transmission with the total convenience of an automatic, the new seven-speed MCT with AMG Speedshift is an all-new design available only in the new SL63 AMG. Featuring seven speeds, four shift modes and a double-clutching function, the MCT transmission offers impressive versatility and even faster shift times.

At the heart of the new AMG Speedshift MCT seven-speed sports transmission is a new start-up clutch, which runs in an oil bath and replaces a conventional torque converter. Thanks to its low rotational mass, the start-up clutch helps the transmission respond instantaneously and dynamically with no slip.




Fitted with four drive modes: “C” (Comfort), “S” (Sport), “S+” (Sport plus) and “M” (Manual), the transmission provides customized shift control for maximum driving pleasure, and does so with no interruption of power. In Comfort mode, smooth shifts coupled with a “soft” accelerator response are set up for silky smooth power transfer. In Sport mode, the engine and transmission interact quicker – upshifts and downshifts take place at higher engine speed. Gearshifts are around 20 percent faster than in Comfort mode. Switching to the Sport Plus mode cuts another 20 percent off shift times, while the sportiest mode, Manual, reduces shifting times by another 10 percent – a total reduction of 50 percent compared with Comfort mode. In Manual mode, the gearshifts take just 100 milliseconds.

Ultra-fast, spontaneous multiple downshifts are another forte of the new MCT sports transmission. For instance, kickdown will shift directly from seventh down to fourth gear or from fifth to second. In the “S” (Sport), “S+” (Sport plus) and “M” (Manual) modes, an automatic double-clutching function is active. Every manual or automatic downshift is accompanied by precisely metered double-clutching – from “S” through “S+” to “M” incrementally. Not only does double-clutching make driving more fun, but virtually load-free downshifting minimizes any jerking, a special benefit when braking into a curve.

The First Engine Developed From the Ground Up by AMG

The SL63 AMG is powered by an AMG 6.3-liter V8 engine that features four valves per cylinder, variable valve timing, bucket tappets (rather than rocker arms) and a variable intake manifold. Sharing no parts with Mercedes-Benz V8 engines, the 6.3-liter engine was a completely autonomous development at AMG.

Built almost completely from a high-strength silicon-aluminum alloy, the cylinder bores make use of a twin-wire-arc-sprayed (TWAS) coating, a process that results in impressively low friction and running surfaces that are twice as hard as conventional cast-iron cylinders.

The 6.3-liter engine block boasts an especially rigid bedplate acting as the overall support of the main bearings (similar to a one-piece set of main bearing caps), cast-in steel reinforcements and a sturdy closed-deck layout in the cylinder head area. The high-flow intake and exhaust ports form a vertical straight line, helping the 6.3 AMG engine rev freely to more than 7,000 rpm, yet the highly flexible AMG engine still produces nearly 90 percent of its peak torque at only 2,000 rpm.

A finely balanced crankshaft with six counterweights spins in five main crankshaft bearings. The crankshaft counterweights feature heavy metal plugs – a detail usually found only in racing engines – which means they can be significantly smaller, increasing power by reducing rotational inertia and oil drag.

Each forged connecting rod is precisely “cracked” with the help of a laser beam, so the irregular fracture contributes to its strength when the two halves are clamped around the crankshaft. The connecting rods and lightweight pistons are matched for extremely close weight tolerances that contribute to smooth running at high speeds. Small nozzles in the engine block spray cooling oil onto the underside of each piston crown.


The World’s Safest Convertible

Widely acclaimed as one of the world’s safest convertibles, the SL provides sports car performance with all the built-in safety that’s expected from Mercedes-Benz. Since an open car can leave its occupants vulnerable in a rollover, Mercedes engineers met the challenge in the SL with the world’s first automatic roll bar.

Normally part of the interior’s rear-compartment surround structure, the padded, leather-covered bar pops up, locking in place in a third of a second if sensors detect an impending rollover. The driver can also raise and lower the bar by a switch on the console.

Shoulder belts are integrated directly into the seats for greater occupant protection, especially in roll­overs. The Mercedes SL was also the first car with side airbags, which are part of a safety system that includes dual front airbags and emergency tensioning retractors that tighten the seat belts in a collision.

V8 and V12 Power

The two AMG SL roadster models for 2009 feature a choice of V8 and V12 power. The SL63 AMG is powered by a 6.3-liter four-valve-per-cylinder V8 with 518 horsepower and 465 pound-feet of torque, while V12-powered SL65 AMG, makes 604 hp and a monstrous 738 lb.-ft. of torque.

AMG High-Performance Braking

Excellent stopping power for the SL is provided by large, four-wheel disc brakes enhanced with four-channel ABS anti-lock control. Matched to its power and speed capability, the SL63 AMG comes with large 14.2-inch vented rotors up front and 13.0-inch vented rotors at the rear, while the SL65 AMG boasts vented discs that are another 1.2 inches in diameter.

Also new are 19-inch AMG staggered-width alloy wheels – 8.5 and 9.5 inches wide – fitted with 255 / 35 R 19 (front) and 285 / 30 R 19 (rear) tires. With triple-spoke styling and a titanium grey finish, the AMG alloy wheels complement the new AMG body styling.

ABC Active Suspension Gives Cat-Like Agility

The SL chassis uses a fully independent, double-control-arm front suspension and the patented Mercedes-Benz five-link rear suspension. All SL models come with second-generation Active Body Control (ABC), the Mercedes-Benz active-suspension technology that virtually eliminates body roll in cornering, squat under acceleration and dive during braking.

Each SL uses software programming specific to the model, akin to tuning the spring rates, shock damping and roll stiffness of a conventional suspension. Special AMG struts with firmer damping and fully reworked systems such as ABS anti-lock brakes, Brake Assist, ASR traction control and ESP stability control complement the enhanced AMG chassis.