Automotive Intelligence - the web for automotive professionals and car enthusiasts
May 10, 2012
The eight-cylinder powerplant with the abbreviation M 157 features a combination of innovative high-tech components – for high power output – and delivers exemplary, low fuel consumption. In addition to spray-guided direct petrol injection, the engine boasts an all-aluminium crankcase, twin turbochargers, four valves per cylinder with camshaft adjustment, air/water intercooling, alternator management and an ECO start/stop function. The weight-optimised AMG sports exhaust system with two chromed twin tailpipes produces a distinctive engine sound.
The key data at a glance:
* with AMG Performance package ** electronically limited
Intelligent lightweight construction is one of the major factors behind the low fuel consumption figures. The SL 63 AMG is based on a lightweight all-aluminium bodyshell similar to that of the SLS AMG super sports car. Compared with the preceding model which featured a steel construction, this design not only delivers a significant weight saving of around 110 kilograms, it also greatly enhances rigidity, safety and comfort. Intelligent lightweight construction also means that the components have been optimised in line with their specific purpose. Various types of processing are used for the aluminium components, for instance, which are produced as permanent mould castings (reusable metallic casting mould) or vacuum die castings before being processed into extruded sections or used as sheet aluminium with varying wall thicknesses. The result is high rigidity, high safety and improved vibration characteristics. For the cover behind the tank, the designers use even lighter magnesium material in some cases. High-strength steel tubes are integrated into the A-pillars for safety reasons.
The boot lid helps to further trim the weight. For the first time on a volume-produced model, the inner support is made from lightweight carbon-fibre composite material. The extremely rigid carbon-fibre component is bonded to the plastic outer shell, resulting in a weight saving of five kilograms compared with a conventional boot lid – an innovative solution that is being pioneered with the SL 63 AMG. This raft of innovative lightweight design measures means that, at an EC kerb weight of 1845 kilograms, the new SL 63 AMG is 125 kilograms lighter than the model it is replacing.
The lightweight design measures are not just limited to the body of the SL 63 AMG, however, as the steering knuckles and spring links on the four-link front suspension and almost all of the multi-link independent rear suspension's wheel location components are made of aluminium. The reduction in unsprung masses enhances both agility and the response characteristics of the spring-and-damper units.
Mercedes-AMG is remaining faithful to the ABC active spring and damper system: the new SL 63 AMG is equipped with an enhanced version of the AMG sports suspension based on Active Body Control as standard. During the design, development and testing phases, the focus was firmly on driving dynamics and performance. To enable greater agility and faster cornering speeds, the SL 63 AMG has more negative camber all round and fully revised elastokinematics. Exceptionally sporty characteristics with reduced roll angles and firm body damping ("Sport") or more comfort-oriented settings for a high level of comfort on long journeys ("Comfort") can be selected at the push of a button.
Equipped with the new, electro-mechanical AMG speed-sensitive sports steering, the flagship AMG model impresses with its fleet-footed, agile cornering and exceptional feedback at the critical limits. The steering has a constant and more direct ratio, and variable power assistance which adjusts in line with the suspension settings. Further standard equipment includes 3-stage ESP®, a speciality exclusive to AMG with "SPORT Handling" mode for particularly keen drivers, while options available from the AMG Performance Studio include an AMG rear axle differential lock and AMG performance suspension.
Power transmission can likewise be adapted to specific requirements, as the AMG SPEEDSHIFT MCT 7-speed sports transmission has four modes to select from: "C" (Controlled Efficiency), "S" (Sport), "S+" (Sport plus) and "M" (Manual). In "C" mode, the ECO start/stop function is active and switches off the eight-cylinder engine when the vehicle is at a standstill. Plus the transmission characteristics are tangibly soft, with smooth and early gear changes. Second gear is generally used as the starting gear in this mode.
The engine and transmission are far more agile in "S", "S+" and "M" mode; in addition, the ECO start/stop function is deactivated. Partial suppression of the cylinders proves perfect for a committed driving style: briefly and precisely interrupting ignition and injection under full load leads to even faster gearshifts than before. A welcome side effect of this is the emotive sound impression. An automatic double-declutching function for downshifting and the RACE START function are also included as standard with the AMG SPEEDSHIFT MCT 7-speed sports transmission.
Maximum performance is also a top priority when it comes to braking: the newly developed AMG high-performance composite braking system features 390 x 36 mm composite discs with six-piston fixed callipers at the front and 360 x 26 mm integral discs with single-piston floating callipers at the rear. An electric parking brake is fitted as standard, while options available from the AMG Performance Studio include red-painted callipers to denote the AMG Performance package and the even more high-performance, weight-optimised AMG ceramic high-performance composite braking system as seen on the SLS AMG.
The SL 63 AMG leaves the factory fitted with five-twin-spoke AMG light-alloy wheels painted in titanium grey with a high-sheen finish, complete with 255/35 R 19 front and 285/30 R 19 rear tyres. Multi-spoke AMG forged wheels painted in titanium grey and with a polished finish from the AMG Performance Studio with 255/35 R 19 front and 285/30 R 20 rear tyres – also available in matt black including a rim flange with a high-sheen finish – help to reduce the unsprung masses.
The new Mercedes-Benz SL 63 AMG will be launched in May 2012. Prices in Germany at a glance (incl. 19% VAT): SL 63 AMG: €157,675 - AMG Performance package: €14,280.
(May 09, 2012)