Mercedes-AMG is embarking on the 2012 roadster season in inimitably dynamic style: following on from the recent launch of the SL 63 AMG, the top eight-cylinder model, there now comes the presentation of the new Mercedes-Benz SL 65 AMG, the V12 roadster in the line-up from the Stuttgart-based manufacturer.
The AMG 6.0-liter V12 biturbo engine generates a peak output of 621 hp and a maximum torque of 738 lb-ft. The result: exceptional performance, impressive power delivery and effortlessly superior dynamics. The use of an all-aluminum body-in-white delivers a drastic weight reduction as the MY13 SL65 AMG is 254 pounds lighter than before. The distinctive front end is dominated by the new "twin-blade" grille with two blade-shaped fins and the lower horizontal bar in the front skirt in high-gloss chrome.
"The combination of exclusive V12 dynamics and cultivated roadster pleasure was already unique in the previous model. We are certain that, with the new SL65 AMG, we have developed a stunning high-performance automobile beyond compare for a small, but loyal fan base," says Ola Källenius, CEO of Mercedes-AMG GmbH.
The intelligent lightweight design of the bodyshell also contributes to the reduction of fuel consumption. A key element in the improved fuel efficiency is the result of the AMG SPEEDSHIFT PLUS 7-Speed transmission, the ECO stop/start function, and improvements to the internal efficiency of the engine and alternator management. Despite a considerable improvement in fuel economy, the peak output of the AMG 6.0-liter V12 biturbo engine is up from 604 hp to 621 hp. The maximum torque stands at a mighty 738 lb-ft.
This unparalleled output provides amazing propulsion for the new SL65 AMG – acceleration from 0 to 60 mph takes 3.9 seconds. Top speed in the U.S. market stands at 186 mph. The key attributes of the AMG biturbo twelve-cylinder include its heart stopping acceleration, and seamless power delivery combined with a distinctive AMG V12 soundtrack. In short, the SL65 AMG captures the imagination with its refined, stylish performance.
The AMG 6.0-liter V12 biturbo engine (M 279) is based on the previous M 275 unit and has been extensively developed for its application in the new SL65 AMG. New turbochargers with an enlarged spiral cross-section, new manifolds and wastegate channels optimized for airflow deliver an additional 17 hp. The multi-spark ignition with twelve twin ignition coils not only makes for smoother running, but also works together with a new, more powerful engine management and optimized cylinder heads to provide even more effective combustion. The outcome is fewer exhaust emissions, which is also in large part due to the optimized catalytic converter system.
The redeveloped AMG sport exhaust system incorporates a modified pipe layout for improved flow coupled with a weight reduction of seven pounds resulting from reduced wall thicknesses.
And it is not just the inner attributes of the AMG 6.0-liter V12 biturbo engine that are stunning – the engine also looks inspiring. The carbon-fiber and aluminum engine cover further underscores the exceptional nature of the powerful twelve-cylinder that lies beneath.
For the first time, AMG is combining the 6.0-liter V12 biturbo engine with the AMG SPEEDSHIFT PLUS 7-Speed transmission. The wide ratio spread of the seven-speed automatic transmission delivers significantly lower revving and helps in the reduction of fuel consumption. A new fuel-economy torque converter, reduced-friction bearings and transmission oil thermal management further increase the efficiency of transferring power to the wheels.
The AMG SPEEDSHIFT PLUS 7-Speed transmission features four individual drive programs that can be selected at the touch of a button on the center console – Controlled Efficiency (C), Sport (S), Sport plus (S+) and Manual (M). The ECO stop/start function is always active in C mode. For the greatest sense of involvement and dynamics, there is the automatic double-declutch function for downshifting, as well as brief and precisely defined retardation of ignition and injection during upshifting under full load. The latter also reduces shift times.
Compared to the steel construction of the previous model, the all-aluminum body-in-white of the new SL65 AMG delivers weight savings, as well as superior stiffness, safety and comfort. Intelligent lightweight design also means optimizing components for their specific application. For instance, an array of different aluminum processes come into play - components are made using gravity die casting or vacuum pressure casting, worked into extruded profile or used as aluminum sheet with varying wall thicknesses. The results are a high degree of stiffness and safety and improved vibration characteristics. Engineers made use of the even lighter magnesium for part of the cover behind the fuel tank. High-strength steel tubes are integrated into the A-pillars for reasons of safety.
Further weight reduction comes courtesy of the rear decklid. The internal frame is made from carbon composite material. The plastic exterior shell is then fastened to the extremely stiff carbon component with adhesive. The result is a weight saving of eleven pounds compared with a conventional rear lid. The innovative solution is being used initially in AMG's SL models. The outcome of the many lightweight design innovations is that the curb weight of 4,299 pounds for the new SL65 AMG is 254 pounds less than that of the previous model.
When it comes to the chassis, Mercedes-AMG is focused on lightweight engineering. The four-link front suspension incorporates steering knuckles and control arms in aluminum, which also features in almost all suspension parts on the multilink rear axle. Agility is not the only aspect to benefit from the reduction of unsprung masses; the response characteristics of the spring-and-damper units are also improved. Like the previous model, the new SL65 AMG is fitted with the ABC active suspension system as standard. The AMG sports suspension based on Active Body Control is a further developed version of the setup in the SL63 AMG with the eight-cylinder engine, tuned specifically for this application.
Handling and performance were the top priorities during conception, development and testing. Two chassis settings are available for selection at the touch of a button – a very sporty setting with reduced roll rate and tighter body damping ("Sport") and a program offering a high degree of long-distance comfort ("Comfort"). More negative camber on both axles, plus completely re-engineered elastokinematics deliver increased agility and higher cornering speeds.
The SL65 AMG is clearly recognizable as a stylish and exclusive high-performance roadster not just technically, but also visually. The SL65 AMG is presented for the first time with the new AMG "face". The two dominant visual elements - the grille and the lower air inlet – remain, but have been reinterpreted to give them a more distinctively dynamic and premium look. The central styling feature is the new twin-blade grille finished in high-gloss chrome. The Mercedes star is mounted on two blade-like fins with aerofoil profiles. The stronger arrow-form of the grille optimizes the vehicle's longitudinal proportions, adding even more visual emphasis to the aerodynamic, minimalist design.
The sixth generation of the SL offers a space-saving electro-hydraulic retractable hard-top that converts the SL65 AMG from a roadster to a coupe in less than 20 seconds. In contrast to the previous model, the new SL comes with the unique MAGIC SKY CONTROL. Its transparency can be switched from light to dark at the touch of a button.