It was hardly surprising that in autumn 2011 Mercedes-AMG added a roadster to the SLS AMG Coupé, which had already become an automotive icon. Naturally, it had to do without the gullwing doors of its closed brother, but instead featured a compact fabric soft top that opened electrically in 11 seconds, and the same fascinating high-tech package.
The exterior appearance of the open-top version was also reminiscent of its legendary predecessor, the 300 SL Roadster from 1957. The typical sports car proportions of the two-seater aluminium body were almost maxed out to the extreme: A bonnet almost two metres long, a low roofline typical of a roadster, the emphatically short rear end with extendable rear wing and the overhangs at the front and rear reduced to the technically necessary minimum, combined with the unusually wide track and the large wheels, made for an impressive appearance of the super sports car even when standing still.
In addition, expressive design elements such as the low-slung, swept-back front apron with its recessed sides, the aviation-inspired air outlet grilles on the sides of the car, the fins on the bonnet and the wide rear end set visual accents.
The design language prevailing in the interior of the high-performance roadster was no less orientated towards role models from aviation. The instrument panel and centre console conveyed an authentic cockpit feel, supported by the high beltlines. The design of various operating elements was also reminiscent of aircraft construction practice. Another eye-catching feature was the Performance steering wheel, which was flattened at the bottom and only 365 mm in diameter, with a lower clasp made of real metal, as were the gearshift paddles. The interior was available in six different one-tone leather colours from the desgino range, supplemented by four two-tone combinations in designo Exclusive leather. The A-pillars were trimmed with Alcantara® material.
The equipment level of the two-seater reflected the leading position of the high-performance roadster in the Mercedes-AMG range. For example, the THERMOTRONIC dual-zone automatic climate control system was fitted as standard, as was seat heating in the AMG sports seats, a clip-on wind deflector and the KEYLESS-GO feature with start function. Also included as standard was the COMAND APS multimedia system, which controlled all radio, DVD drive, telephone and navigation functions via a 7-inch colour display integrated into the dashboard, as well as the LINGUATRONIC voice control system, which also came as standard, operated with a rotary pushbutton controller in the centre console.
The AIRSCARF® comfort feature, available exclusively from Mercedes-Benz, was available as an option and supplied the neck and nape of both passengers with warm air via air vents in the head restraints when the soft top was open. The optional Bang & Olufsen BeoSound AMG surround sound system with 11 loudspeakers and an amplifier output of 1000 watts offered special music enjoyment.
As with the Gullwing Coupé, the heart of the new roadster version was the AMG 6.3-litre V8 engine from the M 159 series installed as the front mid-engine. The engine, designed as a high-revving naturally aspirated engine, produced 420 kW/571 hp and also delivered top-class driving performance: The SLS AMG Roadster accelerated from 0 to 100 km/h in 3.8 seconds, and the maximum speed was electronically limited at 317 km/h. The V8, reduced in weight to 205 kg, had a number of technical features from classic racing engine construction, such as dry sump lubrication, forged pistons and flow-optimised tubular steel manifolds.
Despite its enormous performance data, the high-performance engine complied with the Euro 5 emissions standard and used fuel comparatively economically: The average fuel consumption according to the applicable NEDC standard was stated as 13.2 litres per 100 kilometres – a top value in the limited competitive environment, which was achieved not least thanks to accompanying efficiency enhancement measures such as friction-optimised cylinder liners, a map-controlled oil supply and intelligent alternator management.
It goes without saying that the acoustics of the 6.3-litre engine in the roadster were just as emotional as in the coupé. The sound of the AMG sports exhaust system offered an inspiring synthesis of passion and practicality: The soundscape warmed the heart, but never became intrusive.
The immense power of the V8 was transmitted via a carbon-fibre drive shaft to a newly developed transmission with integrated mechanical limited-slip differential arranged on the rear axle in transaxle technology. The AMG SPEEDSHIFT DCT 7-speed sports transmission was a dual-clutch transmission that did not require a hydraulic torque converter and offered extremely fast gear changes without any interruption in tractive force. The AMG DRIVE UNIT offered a choice of four differently tailored drive programs. The "C" (Controlled Efficiency) setting enabled consumption-optimised driving with low gearshift speeds, the "S" (Sport) and "S+" (Sport plus) modes allowed dynamic driving in variously sharpened configurations, while in the "M" (Manual) setting the gearshift paddles were used, shift times were half as short as in the "C" setting and an upshift indicator in the AMG instrument cluster conveyed a pure racing feeling. The latter also applied to the transmission's RACE START function, which ensured perfect traction during acceleration sprints from a standing start.
The drive train was embedded in a completely newly developed spaceframe serving as a supporting structure. Its architecture consisted of lightweight aluminium profiles that connected the load nodes together to form a highly stable structure. Compared to the coupé, the bodyshell of the open-top version was reinforced at the side sills, among other things, to achieve the best possible torsional rigidity. Additional struts were also used, such as a strut brace between the soft top and the tank, as well as a cross member behind the seats. At 1660 kilograms, the weight of the roadster was still only around 40 kilograms more than that of the coupé. Overall, the SLS AMG Roadster had a power-to-weight ratio of just 2.9 kg/hp.
In view of the SLS AMG Roadster's outstanding driving performance, the aerodynamic quality of the body not only played a key role in terms of favourable fuel consumption values, but also in ensuring reliable driving stability at all times. Extensive wind tunnel tests resulted in a combination of low lift on the front axle and slight downforce on the rear axle right up to the top speed range, which ensured that the roadster reacted calmly to steering inputs, especially at high speeds. The rear wing, which automatically extended from a speed of 120 km/h, together with the rear diffuser, provided the desired downforce at the rear axle.
The three-layer fabric soft top of the roadster was characterised by its low weight and low wind noise and hardly affected its wind resistance compared to the coupé. In addition, with its Z-fold, it required very little stowage space despite the glass rear window: At 173 litres, the boot capacity of the open-top version was only 3 litres less than that of the coupé.
In order to be optimally prepared for the worst-case scenario, the SLS AMG Roadster not only featured an elaborately designed, highly stable body structure, but also state-of-the-art restraint systems to protect the two passengers. Among other things, up to eight airbags were on board.
The concept and design of the chassis were adequate in every respect for the available driving performance potential. Here too, the aim was maximum safety and optimum controllability in every driving situation with the greatest possible dynamics and agility, without having to sacrifice the appropriate long-distance comfort. The extremely low centre of gravity of the SLS AMG and the axle load distribution of 47% at the front and 53% at the rear, indicated by the installation position of the V8 behind the front axle, formed an ideal basis for low mass inertia around the vertical axis during sudden changes of direction and also ensured exemplary traction. Aluminium double wishbones with tie rods were used as wheel control elements all round. They guaranteed high camber and track stability and provided optimum road contact. The steering knuckles and wheel carriers, also made of aluminium, additionally reduced the unsprung masses and resulted in a particularly sensitive response of the spring and damper elements.
The purely mechanical rack-and-pinion steering with constant ratio and speed-dependent power assistance was also designed for optimum road contact, while the AMG high-performance braking system with composite brake discs kept the SLS AMG's performance potential safely under control at all times. The optionally available high-performance ceramic composite braking system with additionally enlarged brake discs offered even greater thermal resistance under the most intensive loads. A 3-stage ESP® acted as a safety parachute at the limits of driving physics, allowing the drive slip to be controlled in various modulated forms.
The AMG light-alloy wheels of the open-top super sports car were a visual presence. As standard, 9.5 x 19-inch rims with 265/35 tyres were fitted at the front and 11 x 20-inch rims with 295/30 tyres at the rear. In addition to the 7-spoke rims, 5-spoke rims and further weight-optimised, forged rims with 10-spoke styling were also available. A tyre pressure monitoring system with permanent individual wheel monitoring was always part of the standard equipment.
Delivery of the first vehicles to customers began in October 2011. The gross list price for the roadster was stated as 195,160.00 euros.
Around a year later, in autumn 2012, the GT version of the SLS AMG, which was available for both the coupé and the roadster, added an even more dynamic version of the super sports car to the model range. The high-revving V8 with a displacement of 6.3 litres boasted a peak output of 435 kW/591 hp in the GT. Even more impressive than this increase in power were the now noticeably more spontaneous, almost racing car-like performance characteristics. The revised AMG SPEEDSHIFT DCT 7-speed sports transmission, whose response times between gearshift paddle and gear change were further reduced, made a significant contribution to this. The double-clutching function when downshifting was also even more explicitly tuned.
The new AMG RIDE CONTROL Performance suspension was fitted as standard, with a firmer basic set-up of springs and dampers. In addition, the "Comfort" suspension mode was omitted in the AMG DRIVE UNIT. Forged AMG light-alloy wheels in 10-spoke design were standard equipment on the SLS AMG GT.
On the outside, darkened headlamps and tail lamps lights as well as some high-gloss trim elements indicated the special nature of the new version. The interior of the roadster was dominated by a sporty black outfit, accentuated by numerous details in a contrasting red colour. The grip area of the AMG Performance steering wheel, which was flattened at the bottom, was trimmed in Alcantara®.
The market launch of the SLS AMG GT Roadster started in autumn 2012 at a gross list price of 213,010.00 euros.
For decades, Mercedes-Benz has heralded the approaching end of particularly outstanding passenger car series with the presentation of a specially customised limited edition, the FINAL EDITION. This was also the case with the SLS AMG at the end of 2013. Limited to 350 vehicles, the SLS AMG GT FINAL EDITION, available as a coupé and roadster, boasted a range of exclusive features. The bonnet with central air intake, the front splitter, the fixed rear wing – all finished in visible carbon fibre – and the forged AMG light-alloy wheels in cross-spoke design, for example, conveyed an enhanced visual presence.
In the interior, a standard designo Exclusive leather interior with diamond design on the seat and door centre panels created a stylish ambience. Silver contrasting topstitching and other high-quality details, such as a fine Alcantara® strip on the leather cover of the instrument panel and the plaque with engraved limited edition number on the carbon centre console, underlined the individual character of the edition model.
In technical terms, the SLS AMG GT Roadster FINAL EDITION was based on the performance-enhanced GT version. It still used the 435 kW/591 hp V8 engine, AMG SPEEDSHIFT DCT 7-speed sports transmission and AMG RIDE CONTROL Performance suspension.
The final chapter in the SLS AMG story also began for the open-top version with the market launch of the edition model in spring 2014. The gross list price of the roadster, whose production ended in June of the same year, was 233,835.00 euros.
Compared to the iconic Gullwing Coupé, the SLS AMG Roadster – adjusted for its production cycle of just under three years – proved to be less in demand in the final tally. Between 2011 and 2014, only just under 2300 units of the basic model were produced. However, the relative share of the GT version, which was only available from the beginning of 2014, was significantly higher than that of the coupé at exactly 507 vehicles.
