The next SL was presented to the press in July 2001 at Deichtorhallen in Hamburg. Owing to a combination of advanced electronic chassis systems which was unique in the world at the time, the R 230-series SL offered an outstanding driving experience coupled with highest levels of operating safety and so set trends for sports cars and car manufacture in general.

At market launch, the first model available was the Mercedes-Benz SL 500 with an output of 225 kW. In autumn 2001 it was joined by the SL 55 AMG with a supercharged V8 engine and 350 kW. In 2002 the SL 350 featuring a 180 kW 3.7-litre V6 engine followed, and in January 2003 finally Mercedes-Benz introduced the SL 600 with the powerful 368 kW 5.5-litre V12 biturbo engine as new flagship model.

The comprehensive standard equipment of the SL included, for example, leather-upholstered integral seats plus memory function for the electric seat and steering wheel adjustment (additionally stored in the electronic ignition key); multifunction steering wheel, automatic climate control and stereo car radio.
As optional extras, innovative assistance systems like the DISTRONIC proximity control, the automatic emergency call system TELEAID, the control and display system COMAND or the electronic tyre pressure monitoring system were available. Leather, fine wood and aluminium are the materials used to ensure the typical exclusivity and perceived value of the SL. There was a choice of two types of leather, four high-quality trim variants and five appointment colours. Matt-finished chrome framed the four individual, classic chronometer-style instruments in the cockpit and also could be found in other details of the interior.

The design unites tradition and future
The design of the R 230 series blends tradition and future through distinctive details. For instance, the air intakes in the front wings take up a typical feature of the 300 SL from the 1950s. The thin, wing-like segments on these side air intakes – called fins by experts – also are a reminiscence. The designers use this stylistic element additionally to give a sporty touch to the grilles of the openings on the bonnet.

The horizontally stretched radiator grille has always been an unmistakable feature of the SL. The R 230 took up this tradition, but showed it in an up-to-date interpretation, thrusting a louvred radiator grille with a flatter slope than previously into the wind. This made the front end, in combination with the more pronounced wedge shape of the body, appear very dynamic and powerful. The four louvres encompassed the Mercedes star, which in its accustomed size and position clearly indicates the brand to which the two-seater belongs.

These typical SL features harmonised with the new elements, the headlamps, for example: on each side two of the familiar four “eyes” merge into one without giving up their basic oval shape. The up-to-date clear-lens look effectively enhanced the standard-fit bi-xenon headlamps and gave an additional pinch of brilliance to the front design.

The long bonnet took up the curves of the headlamps and carried them towards the rear in a tense arch. The design of the seemingly muscular wings also evolves from this ensemble. The soft lines of the bonnet and wings merge smoothly into the taut lines that give structure to the sides of the body at the shoulderline. Another line develops in the lower part of the wings from the verve generated by the side air intakes. It gives a formal hold to the large, quiescent surfaces of the doors and creates a visual bond with the rear end. The steeply raked windscreen emphasises the sports car character and accentuates the low, wedge-shaped silhouette.

16 seconds of roof acrobatics
Unlike its predecessors the R 230-series SL always carries its hardtop with it. The integration of the SL’s vario-roof into the car’s flowing lines is proof of the car’s high design quality.

At the push of a button, or via remote control, the roof can be opened or closed within 16 seconds. An extremely complex swivelling mechanism ensures that the three roof components disappear into the upper part of the boot in a space-saving way. Underneath it, 235 litres of luggage space are available. With the top up, the vehicle offers 317 litres of space, inclusive of the luggage holder in the spare wheel recess – 52 litres more than the previous model. Since mid-2002 a glass roof variant is also available.

Further features underscored the impression of dynamism and elegance created by the R 230 series, for example the body with the powerfully shaped front apron, the muscular curves and the pronounced wedge shape, but also stylistic elements like the distinctive outline of the side skirts, the wide wheels (diameter: 43.18 centimetres) or the oval tailpipes of the exhaust system. All body parts – from door handle to bumper –were painted the colour of the car so that from a formal viewpoint and colourwise the sports car appears all of a piece.

This also applied to the rear end, characterised by large, triangularly shaped tail lights. Here again there was no play of colours, but elegant consistency: the tail light lenses were coloured a uniform red – special filters in front of the reflectors ensured that the indicators still appeared yellow and the reversing light white.

Sensotronic Brake Control SBC™
The technical innovations of the R 230 series include the electrohydraulic braking system Sensotronic Brake Control SBC™, which had its premiere in this series. It operates in conjunction with the Electronic Stability Program ESP® and the active suspension system Active Body Control ABC, which minimises body movements or any tendency to skid during cornering and braking.

Sensotronic Brake Control SBC™ also was a gateway to the world of future “by wire” systems that no longer transmit the driver’s commands mechanically or hydraulically, but electronically – by cable. The most important performance characteristics of SBC™ include extremely dynamic brake pressure build-up and a reliable “feel” for driver and vehicle behaviour owing to sophisticated sensor technology.

For example, the system diagnoses a rapid shifting of the driver’s foot from the accelerator to the brake pedal as evidence of an emergency situation, automatically increases the pressure in the brake lines and simultaneously positions the brake pads on the brake discs so that they can grab the disc without delay and with full force when the driver depresses the brake pedal. The effect is that the stopping distance is three percent shorter in an emergency stop.

In addition, thanks to variable brake force distribution SBC™ affords more safety when braking on bends or on difficult surfaces, depending on wheel contact force and slip. Owing to greater dynamics and precision SBC™ also enhances the performance of the Brake Assist BAS and the Electronic Stability Program ESP®.

This package of highly efficient electronic control systems initiated a revolutionary trend in automobile manufacture in the area of chassis, handling safety and driving dynamics.

Suspension with Active Body Control ABC
These systems are supported by wheel suspensions which react sensitively in conjunction with the Active Body Control ABC. At the front a state-of-the-art four-link system ensures optimal road roar and tyre vibration characteristics, precise wheel location and steering. The lower elements of the front axle, the steering gear of the rack-and-pinion steering, and the engine mounts are connected with an aluminium frame-type integral support which also celebrated its premiere in the new SL.

In the SL of the R 230 series the multi-link independent rear suspension, still unsurpassed for wheel location, is made entirely of aluminium for the first time, including wheel carriers and subframe. To improve the oversteer/understeer characteristics even more, the axle geometry was modified in detail.

Safety redefined
Ever since the “Pagoda” the abbreviation SL is synonymous with pioneering achievements in the areas of active and passive safety in open-top sports cars. With an entirely new, comprehensive concept the R 230-series SL clearly outstrips the previous safety standards to make it a model in the area of vehicle safety in particular for sports cars. The concept makes allowance for all aspects of active and passive vehicle safety – from accident avoidance with the aid of electronic handling dynamics systems like SBC™, Active Body Control ABC, Brake Assist BAS, acceleration skid control ASR or ESP®, to the structural integrity of the body with a high level of passenger cell rigidity in every conceivable type of accident.

Some of the things contributing to occupant protection together with the high-strength body structure: two-stage airbags for driver and front passenger, new head/thorax bags in the doors, newly developed integral seats, high-performance belt tensioners, belt force limiters, or the sensor-controlled roll-over bar, which goes into action even when the vario-roof is closed.

In the event of an accident the automatic emergency call system TELEAID (optional extra) developed by Mercedes-Benz ensures that emergency doctor and police are automatically alarmed and guided to the accident scene by satellite navigation.

Safety development between rating tests and reality
The R 230 SL series has passed the most rigorous crash tests such as an offset frontal impact at 64 km/h or the 90-degree side collision at 50 km/h, both of which are included in the European NCAP (New Car Assessment Programme) procedure and which make highest demands of the vehicle structure especially in the case of open-top cars. The engineers have devoted just as much attention to the aspect of ease of repair, which they investigate in frontal and rear impacts at a collision speed of 15 km/h in each case. The body structure of the SL affords greatest possible safety to occupants and meets the objective of reasonably priced repair.

In a frontal or rear collision at speeds above 15 km/h the bodyshell structure of the SL provides an exemplary high level of occupant protection owing to many innovative details. Around 33 percent of the bodyshell is made of high-strength sheet affording maximum resistance despite minimum material thickness. All components crucial to crash safety and body stiffness are made from high-strength steel sheet. The fuel tank is made of sheet steel and is located in a protected position above the rear axle.

Fuel economy a high priority
Fuel economy in the R 230-series SL is a topic which runs like a thread through many chapters of the design specifications. The lightweight body plays a decisive role in achieving a favourable fuel economy in all variants: bonnet, front wings, doors, boot lid, tank partition and other components consist of aluminium; especially the 1.40 metre long bonnet is a remarkable lightweight component.

The well-thought-out aerodynamics of the smooth body including underbody, designed to reduce drag, helps to save fuel as well as to minimise noise. The coefficient of drag of 0.29 for the closed car is considered a very remarkable figure; in the previous R 129 it was still 0.32 with hardtop. The open-top SL of the R 230 series has a Cd of only 0.34 (R 129: Cd = 0.40 with side windows closed).

Debut with the SL 500
In summer 2001 the SL 500 debuted first, featuring a 5-litre V8 engine (M 113) delivering 225 kW and torque of 460 Newton metres. It was one of the most powerful engines of its segment, did clearly better than the stringent EU 4 emission standards required, and accelerated the SL 500 from 0 to 100 km/ in 6.3 seconds. The top speed was 250 km/h (electronically governed). The proven five-speed automatic transmission with electronic control, two shift programs and torque converter lockup clutch were standard equipment in the SL 500. A newly developed Touchshift permitted very fast manual gear-changing.

In September 2001 the SL 55 AMG premiered at the Frankfurt International Motor Show. Equipped with a new V8 supercharged engine, it was the most powerful Mercedes-Benz passenger car at the time. The 5.5-litre power plant (M 113) developed 350 kW and delivered a maximum, constant torque of 700 Newton metres from 2650 rpm to 4500 rpm. The car spurted from 0 to 100 km/h in 4.7 seconds; the electronically limited top speed was 250 km/h. The engine was combined with a five-speed automatic transmission including shift buttons on the steering wheel.

The AMG version was distinguishable on the outside from the SL 500 among other things by bumpers with an even more powerful styling, distinctively shaped side skirts, dark-tinted tail lights, exclusive multi-spoke wheels (diameter: 45.72 centimetres) and four chrome-plated exhaust pipes.

In the interior, the more firmly upholstered integral seats with a special perforation and coloured topstitching, high-quality aluminium trim elements with a sand-cast look, and cockpit instruments with light dials, silver-coloured symbol disks and red needles emphasised the character of this sports car.

In 2002 came the SL 350 with a 180 kW 3.7-litre V6 engine (M 112). It accelerated the car in 7.2 seconds from 0 to 100 km/h and gave it an electronically limited top speed of 250 km/h. The standard transmission was the SEQUENTRONIC automated six-speed manual transmission operated via two shift paddles on the steering wheel. The electronically controlled five-speed automatic transmission with Touchshift was available as an optional extra.

A V12 engine in the flagship model
In January 2003 Mercedes-Benz presented the SL 600 with 368 kW 5.5-litre V12 biturbo engine (M 275) as new flagship of the series. It produced tremendous 800 Newton metres of torque, already available at 1800 rpm and constant up to 3600 rpm. The newly developed Mercedes-Benz twelve-cylinder engine with two turbochargers and air-to-water intercooler, three-valve-per-cylinder technology, alternating-current twin-spark ignition and other high-tech innovations is one of the most advanced passenger car engines in the world. It affords effortless superiority in any driving situation. The SL 600 needed only 4.7 seconds to go from 0 to 100 km/h. The top speed was electronically limited to 250 km/h.

From the outside the SL 600 can be recognised by a radiator grille with discreet chrome inlays, silver-painted brake callipers, V12 emblems on the side air intakes, bi-xenon headlamps and exclusive light-alloy wheels. The front wheels have tyres of size 255/40 R 18, the rear wheels tyres of size 285/35 R 18.

Only twelve units: SL 350 “Mille Miglia Edition 2003”
Based on the SL 350, in June 2003 Mercedes-Benz presented the special model “Mille Miglia Edition 2003” to commemorate the legendary road race. Only twelve were built. They were painted in a special “Silver Arrow” metallic finish and had matt-finished aluminium shoulderline trim strips, beautifully designed light-alloy wheels (diameter: 45.72 centimetres), wide-base tyres of size 255/40 ZR 18 (front) and 285/35 ZR 18 (rear) and “Mille Miglia” badges in the air outlet grilles of the front wings and on the boot lid.

The vario-roof of the special model was made of glass and gave the passengers a panoramic view. The special features in the interior included two-tone nappa leather appointments: the seats were in “classic red”, an accent colour already used in the legendary SL sports cars of the 1950s. The roof was lined with soft Alcantara, and the trim elements on the centre console and the doors were aluminium with a matt-finished surface. With the aid of a new laser technique the designers worked the “Mille Miglia” logo and even the course of the thousand-mile race into the leather covers of the head restraints.

Other standard equipment items on the special model included the control and display system COMAND, the parking assist PARKTRONIC, multicontour backrests, CD changer and sound system. The V6 engine of the special model was combined with a five-speed automatic transmission as standard.

A special model on the 50th birthday
In 2004 Mercedes-Benz celebrated the appearance of the 300 SL in 1954 with the special model “Edition 50”, available as SL 350 and SL 500 in a series limited to a total of 550 units. The visual highlights included a matt silver-painted radiator grille with chrome trim strips, light-alloy wheels (diameter: 45.72 centimetres) in turbine design, shoulderline trim strips in a high-sheen finish, a draught-stop frame with high-sheen finish or the darkened tail lights.

In the interior, the instrument cluster was trimmed with a leather/Alcantara combination. The seats, luxury climatised seats with multicontour function as standard, had nappa leather covers; the head restraints showed a lasered “Edition 50” logo. The trim elements in the interior were made of a decorative new aluminium material or, alternatively, black ash wood. Depending on personal taste, if desired the leather appointments also could be had in two-tone condor silver/black or single-tone designo black with topstitching in quartz. A comprehensive range of standard equipment was included: for example, the radio/navigation system COMAND APS with CD changer and surround sound system, but also bi-xenon headlamps with headlamp cleaning system and PARKTRONIC.

2006: facelift for the R 230 series
Five years after launch, Mercedes-Benz upgraded the SL. The 2006 Geneva Motor Show was chosen as debut event. In particular the engines, drive system and suspension were given a sportier tuning.
The V8 engine (M 273) of the SL 500 is a new design; it now has a displacement of 5.5 litres and develops an output of 285 kW. The 0 to 100 km/h acceleration is 5.4 seconds. In the USA the vehicle is sold as the SL 550.

The six-cylinder engine of the SL 350 also is a new development. The 200 kW V6 power plant (M 272) delivers about eleven percent more output while enabling fuel savings of more than one litre per 100 kilometres. The combined NEDC consumption is 10.3 litres per 100 kilometres. The SL 350 accelerates from 0 to 100 km/h in 6.6 seconds and is thus over half a second faster than the previous model.

At the top of the model range is the V12 biturbo engine of the SL 600. Its output rose to 380 kW; the maximum torque, to 830 Newton metres. With the twelve-cylinder engine this SL speeds from 0 to 100 km/h in just 4.5 seconds.

The V6 and V8 models of the facelifted SL-Class are equipped as standard by Mercedes-Benz with the 7G-TRONIC seven-speed automatic transmission. The actively regulated suspension system Active Body Control ABC (standard equipment for the SL 500 and SL 600, optionally available for the SL 350) was further improved. It now reduces body movements in dynamic handling situations by as much as 60 percent versus the previous model.

The body design also has been discreetly updated to include new bumpers with three large openings for cooling air, a more pronounced wedge shape, and fog lamps with chromed trim rings. The radiator grille now has three louvres with chrome elements and is painted matt silver. New light-alloy wheels make for an impressive side view. The horizontally divided tail lights with red-and-white covers in clear-lens look make the muscular rear end of the SL appear still broader.

The interior was also redone, for example showing leather upholstery with a softer grain, new interior colours, aluminium trim elements with a prism pattern, and metal door sills embossed with Mercedes-Benz lettering.

From spring 2007, for models SL 350 and SL 500 a Sports package has been available for 2975 euros extra. It sets the tone in the interior with contrasting topstitching in silver, perforated leather and aluminium trim elements. The look is determined among other things by large five-spoke light-alloy wheels (diameter: 48.26 centimetres) behind which silver-painted brake callipers are visible. Perforated brake discs at the rear conduce to excellent deceleration. The 7G-TRONIC Sport automatic transmission with shift paddles on the steering wheel also is included in the configuration. The distinctive visual features furthermore include darkened tail lights.

In 2008 a comprehensive package of refinements then was applied to the R 230 series. The proven vehicle range was retained but supplemented by the SL 280 (170 kW) with 3.0-litre V6 engine (M 272), so that there are now two six-cylinder models; both engines are based on the same basic unit and have the same engine number. Also available is the SL 63 AMG, whose naturally aspirated V8 engine (M 156) develops 386 kW; as transmission it has the AMG Speedshift MCT, which features a so-called wet start-up clutch instead of a torque converter.

The most conspicuous element of the model refinement package is the new front design: it adapts the SL to the brand’s current car design and focuses attention on a broad and thus very dominant radiator grille. It enhances the powerful look of the SL face, which appears surprisingly new but at the same time very familiar. Powerdomes on the bonnet enhance the vehicle’s strong visual impression. At the rear a newly designed diffusor-look bumper creates associations with racing.

The list of further refinements for the facelifted SL-Class is long. The technical innovations now include the optional Direct-Steer system, the Intelligent Light System with five light functions adapted to typical driving situations, and the neck-level heating AIRSCARF invented by Mercedes-Benz, which can extend the open-top driving season into the cooler time of the year.

The R 230 series in the press
Regarding the Mercedes-Benz SL of the R 230 series, auto motor und sport, Germany, No. 12, 2004, noted in a test report on the SL 500: “Lots of comfort, lots of safety, solid design, a pinch of sportiness, horsepower à la carte, plenty of fresh air and, as of most recently, a hardtop in the boot – this rare blend secures the two-seater a special position that makes it virtually unrivalled.”

Autorevue, Austria, No. 7, 2008, describes the stages of open-top driving in a Mercedes-Benz SL 350 in these words: “Progressive climate stages on a cool evening: first you raise the front and rear side windows, then you ask the passenger to put up the draught-stop. Then you might switch off the seat ventilation and switch on the seat heater. The air conditioner radiates basic warmth. The Airscarf – that seductive neck-level heating system that we miss on the sofa in our living room – follows, in three heat levels. Last stage is the big roof number, amazingly graceful. And everything’s just fine.”

Shortly after the debut of the Mercedes-Benz SL 65 AMG Black Series Road & Track, USA, No. 1, 2009, wrote: “Will anyone buy an SL 65 AMG Black Series for street use? Probably not. But for those few who might, the car is quite civilized on the road. The ride is firm, but not overly so. To truly appreciate the incredible prowess of the SL Black Series, take the car to the track. Its sheer power and speed, together with confidence-inspiring handling, make it one of the most satisfying supercars in the world.”

Source: Daimler AG