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Totally new Mercedes-AMG SL: Premium roadster just keeps getting better

Is it too early to dream about summer? Let's do it anyway and think about the all-new Mercedes-AMG SL, which will be available as a luxurious soft-top 2+2-seater with two handcrafted V8 biturbo engine options: the 577-hp top model SL 63 and the 469-hp SL 55. For the first time in 70 years, the SL is available with all-wheel drive and rear-wheel steering, and the overall design is so fresh that no part of the body shell was adopted from the predecessor or any other model series.

In the SL 63, the V8 engine develops 577 hp and provides a maximum torque of 590 lb-ft over a wide rev range from 2,500 to 4,500 rpm. It goes from 0 to 60 mph in an estimated 3.5 sec. In the SL 55, the V8 engine delivers 469 hp and a peak torque of 516 lb-ft. The sprint from standstill to 60 mph takes 3.8 sec. It is a racier engine under AMG, since its predecessor model only offered a V6.

The AMG 4.0-liter V8 engine has many upgrades, but it still operates with biturbo charging, in which the two turbochargers are not located on the outside of the cylinder banks, but in between them in the cylinder-V. The advantages of the "hot inside V" include: a compact engine design, spontaneous response of the turbochargers, and low exhaust emissions thanks to optimal airflow to the close-coupled catalysts.

Engine features also include weight-optimized pistons, an adapted air intake and intercooling system, as well as extensive software developments. The jet-guided direct petrol injection with piezo injectors, all-aluminum crankcase, 4-valve technology with camshaft adjustment, air-to-water intercoolers, alternator management, ECO start/stop function, and gliding mode have been retained.

The enlarged dimensional concept with 2+2 seats offered the designers more freedom in their design possibilities. It is about 3 in. longer and 1.5 in. wider than the previous model. The long wheelbase, short overhangs, and steeply raked windscreen with black-painted frame make the SL look compact and low. Hallmark SL proportions such as the long hood and the passenger compartment set far back herald a luxurious sports car that is also very suitable for everyday use. Overall, the design is noticeably rounder than its predecessor, with a blunt tail and smoother lines, but it still comes off as muscular and beefy.

The SL was created on an all-new roadster architecture with a composite aluminum structure. The design guarantees maximum rigidity and forms the perfect basis for precise driving dynamics, high comfort, optimal packaging, and sporty body proportions. Compared to the previous model series, the torsional rigidity of the body shell structure increased by 18%. The transverse rigidity is 50% higher than the already outstanding value of the AMG GT Roadster. The longitudinal rigidity is 40% higher. The weight of the plain body shell is around 595 lb. Together with the low center of gravity, the lightweight construction ensures outstanding driving dynamics.

The AMG engine received a new oil pan, repositioned intercoolers, and active crankcase ventilation. The intake and exhaust ducts have been optimized for even more effective gas exchange, and the exhaust gas routing for the catalytic converter box and petrol particulate filter has been enlarged. The developers achieved the increased output of the SL 63 primarily through higher boost pressure and greater air flow, as well as modified engine software. Twenty- or 21-in. aerodynamically optimized alloy wheels are available for the SL.

All of the streamlining design and mechanical elements are seamlessly integrated into the exterior. Further detailed measures reduce the drag coefficient to Cd 0.31, which is an excellent figure for open-top sports cars. The SL's aerodynamics meet the complex requirements of handling stability, drag, cooling, and wind noise. Mercedes says that regardless of whether the top is down or up, the vehicle character and driving characteristics remain unchanged.

A technical highlight in the aerodynamics development is the two-piece, active air control AIRPANEL. The first piece operates with vertical louvers hidden behind the lower air intake in the front bumper. The second piece is located behind the upper air intake and has horizontal louvers. Normally, all louvers are closed. This position reduces drag and allows the air to be directed specifically toward the underbody. This further reduces front lift. Only when certain temperatures on predefined components are reached and the demand for cooling air is particularly high do the louvers open and allow maximum cooling air to flow to the heat exchangers.

Another active component is the retractable rear spoiler seamlessly integrated into the trunk lid. It changes its position depending on the driving status. It factors the driving speed, the longitudinal and lateral acceleration, and the steering speed into the calculation. The spoiler assumes five different angular positions from 50 mph to either optimize handling stability or reduce drag.

The optional AMG Aerodynamics Package includes an active aerodynamic element that is hidden in the underbody in front of the engine. This carbon profile, which weighs around 4.4 lb, reacts to the setting of the AMG driving modes and automatically extends downward by around 1.6 in. at a speed of 50 mph. This creates a Venturi effect, which helps suck the car to the road surface and reduces front-axle lift.

The AMG SPEEDSHIFT MCT (Multi-Clutch Transmission) 9G automatic transmission is specially adapted to the requirements of the new SL. A wet start-off clutch replaces the torque converter. It reduces weight and, thanks to its lower inertia, optimizes response to accelerator pedal commands, especially during spurts and load changes. It includes six driving modes: Slippery, Comfort, Sport, Sport +, Individual, and RACE START (which ensures optimal acceleration from a standstill).

For the first time in its almost 70-year history, the SL is available with a drive system acting on all four wheels. The two V8 models are equipped with AMG Performance 4MATIC+ all-wheel drive technology as standard. This intelligent system combines the advantages of different drive concepts: the fully variable torque distribution to the front and rear axles ensures optimal traction right up to the physical limit. The driver is also able to rely on high handling stability and a high level of safety under all conditions.

The innovative AMG ACTIVE RIDE CONTROL suspension with hydraulic anti-roll stabilization makes its debut in the SL 63. The biggest innovation is that active hydraulic elements replace the conventional mechanical anti-roll bars and compensate for rolling movements of the new SL in fractions of a second. The system enables optimal steering and load-change behavior with AMG-typical driving characteristics in terms of dynamics, precision, and feedback for the driver. At the same time, it increases ride comfort when driving in a straight line and over bumps.

The SL is also equipped with active rear-axle steering as standard. Depending on the speed, the rear wheels steer either in the opposite direction (up to 62 mph) or in the same direction (faster than 62 mph) as the front wheels. The system enables both agile and stable handling -- characteristics that are in contrast to each other without rear-axle steering. Other advantages include easier vehicle control at the limits and less steering effort because the front-wheel steering ratio is more direct.

There is no hard-top convertible offered this time around. The 46-lb reduction in weight by not using the previous metal vario roof has a positive effect on driving dynamics and handling. The space- and weight-saving Z-fold made it possible to dispense with a conventional soft-top compartment cover. The front roof cap ensures that the open soft top is flush with the surface in its final position. Opening and closing takes only about 15 secs and is possible up to a speed of 37 mph.

Inside, the new Mercedes-AMG SL brings the tradition of the first 300 SL Roadster into the modern era. The new edition combines sporting virtues and luxury with a classy, minimalist feel. Fine materials and meticulous workmanship underline the standard of the highest level of comfort.

The head restraints are integrated into the backrest and emphasize the sporty character. The AIRSCARF neck-level heating system is on board as standard: warm air flows into the passenger compartment from air outlets in the head restraints and wraps around the head and neck area of the driver and front passenger like a scarf.

The aero-inspired cockpit design is focused on the driver. The "hyper analogue" design language is exemplified by the fully digital instrument cluster, which is integrated into a three-dimensional visor, and the turbo fan-like air nozzles. The standard MBUX infotainment system offers a choice of several specific display styles and different modes.

The new assistance display in the instrument cluster shows how the driver assistance systems work in a full-screen view. The driver can see their car, lanes, lane markings, and other road users such as cars, trucks, and two-wheelers in an abstracted 3D way there. The system status and operation of the assistants are visualized in this depiction of the surroundings. The new animated assistance display is based on a 3D scene generated in real time. This dynamic, high-quality representation makes the operation of the driving assistance systems transparent as a tangible augmented reality experience.

Pricing has not been released, but it should start at less than $100,000. It's not an AMG GT roadster, but comes close enough for most potential buyers.

Source: Mercedes-AMG

Published November 2021

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