The AMG SPEEDSHIFT MCT 7-speed sports transmission is an all-new, unique concept available exclusively in the new Mercedes-Benz SL 63 AMG. At the heart of this newly developed transmission lies a wet start-up clutch, which runs in an oil bath and replaces the previous torque converter. The resulting direct connection to the powertrain, together with the double-declutching and Race Start functions, guarantees an extremely emotional, supremely dynamic driving experience.

The AMG SPEEDSHIFT MCT 7-speed sports transmission is a newly developed and unique power transfer system. It combines the sporty, direct and agile feedback of a manual transmission and the maximum convenience of an automatic transmission. Fitted with seven speeds, four drive modes, a double-declutching and Race Start function, the AMG SPEEDSHIFT MCT 7-speed sports transmission offers unprecedented versatility. MCT stands for Multi-Clutch Technology and only employs clutch elements to perform gearshifts. Vibrations are effectively eliminated by a new, two-stage torsion damper, with resulting benefits in perceived passenger comfort.

Design measures for a particularly low weight

The high-tech transmission is designed for high torque and maximum revs up to 7200 rpm. It also comes with sufficient reserves even under the highest loads thanks to its high-performance oil cooling system. The AMG sports transmission also impresses with its low weight: at 80 kilograms it even betters the AMG SPEEDSHIFT 7G-TRONIC automatic transmission used in other AMG high-performance cars. This is made possible by dispensing with a torque converter and the use of lightweight magnesium for the transmission housing. Low weight and compact dimensions are also aided by the newly developed, fully integrated transmission control system. The highly efficient electronic control unit is integrated into the sump to save space, and communicates directly with the engine control unit. An 80 MHz processor ensures particularly rapid monitoring and control of all transmission processes.

The AMG SPEEDSHIFT MCT 7-speed sports transmission has been developed jointly by Mercedes-AMG GmbH and Daimler AG, although it will be used exclusively in AMG high-performance vehicles. It is produced at the Mercedes-Benz Esslingen-Hedelfingen production facility, Europe’s largest manufacturer of planetary gear sets.

Compact wet clutch for great agility

At the heart of the new AMG SPEEDSHIFT MCT 7-speed sports transmission lies the wet start-up clutch, which runs in an oil bath and replaces the previous torque converter. Thanks to its low rotational inertia, the transmission responds instantaneously and dynamically with no slip. Accelerator pedal movements trigger an instant traction response. Fitted with four drive modes: “C” (Comfort), “S” (Sport), “S+” (Sport plus) and “M” (Manual), the transmission provides gearshifting with no loss of tractive force and supports customised control strategies for maximum driving pleasure.

In “C” mode the vehicle always starts off in second gear and gearshifts are comfortable, coupled with a “soft” accelerator response set-up for outstandingly smooth power transfer. In “S” mode the engine and transmission interact with more "bite": the engine speed is allowed to reach a higher level in each gear; the downshifts also feel more spontaneous. The gearshifts are also around 20 percent faster than in “C” mode. Switching to “S+” mode cuts another 20 percent off shift times, while “M” is the sportiest mode: here the AMG 6.3-litre V8 engine has even more bite, added to which the transmission shifts gear another 10 percent faster – a reduction of 50 percent compared with “C” mode. In “M” mode the gearshifts take just 100 milliseconds.

Automatic double-declutching function for even more emotional appeal

Ultra-fast, spontaneous multiple downshifts are another forte of the new MCT sports transmission. For instance, kickdown lets you move straight from seventh down to fourth gear or from fifth to second. In the “S” (Sport), “S+” (Sport plus) and “M” (Manual) modes the automatic double-declutching function is active. Every manual or automatic downshift is accompanied by precisely metered double-declutching – from “S” through “S+” to “M” incrementally. And this not only adds to the driver's emotional experience: the virtually load-free downshift minimises load-change reactions, which pays dividends particularly when braking into a bend on the racetrack.

In manual “M” mode the driver also benefits from the high torque of the V8 engine, as there is no automatic downshift under full load and kickdown; the transmission remains steadfastly in the selected gear. Moreover, the AMG MCT sports transmission does not perform an automatic upshift in manual mode when the rev limit is reached. In “M” mode the AMG instrument cluster displays the current gear and alerts the driver to the need for an upshift just before the needle reaches the red zone. This means that a particularly sporty driver can use the superior performance potential to its fullest extent. When approaching the lower rev limit, e.g. when braking the vehicle, there is an automatic downshift to the next lower gear.

AMG DRIVE UNIT with innovative Race Start function

The new AMG DRIVE UNIT is the central control unit for the AMG SPEEDSHIFT MCT 7-speed sports transmission and all driving dynamics functions. The driver can change gears either using the new AMG selector lever with its leather/ carbon-fibre finish, or via the AMG steering-wheel shift paddles. On the left next to the selector lever is the electronic rotary switch to select the four drive modes including activation of the new Race Start function. Underneath are three buttons for additional functions: the first controls the ESP® function, the second the ABC suspension system. The third adorned with AMG lettering is used to store the selected transmission drive mode and the suspension set-up. Briefly pressing the AMG button brings up the configuration options, whilst holding down the button allows you to program the required set-ups - this is confirmed by an acoustic signal. The current settings may be viewed in the AMG instrument cluster by pressing the AMG button at any time.

The Race Start function takes driving dynamics to an entirely new level: it enables the SL 63 AMG driver to call on maximum acceleration, while ensuring optimum traction of the driven wheels. While the vehicle is at a standstill, the driver needs to activate the ESP® sports function and press the brake pedal with their left foot. Having preselected the Race Start program using the rotary switch, a confirma-tion message comes up on the AMG central display. The driver then simply needs to confirm the Race Start function by pulling the “Up” shift paddle once, fully depressing the accelerator and taking his foot off the brake. The optimum start-up engine speed is set fully automatically and the SL 63 AMG accelerates away in an instant – all the way up to top speed, if so required. The driver does not need to shift gear manually; the AMG transmission changes gear with lightning-fast shift times.

























































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