Mercedes SL-Class
For 60 years the two letters "SL" have had a mystical resonance among
automotive enthusiasts. They stand for powerful sportiness, exciting
design, effortlessly superior style, technical innovations and the
ultimate in engineering artistry. The Mercedes-Benz SL-Class inherited
these genes from its forefather, designed as a racing car. In 1952 it
came to the international race tracks, saw and conquered. It was from
this car that Mercedes-Benz derived the first series-production model in
1954, the legendary 300 SL gullwing. And ever since, Mercedes-Benz has
been setting the bar high in the luxury sports car segment with the SL
over five model generations.
The unique combination of systematic sportiness, refined luxury and yet
unrestricted suitability for everyday use at the same time is what makes
the Mercedes-Benz SL-Class the dream car it is - and it is also what
lies behind its success where sales are concerned. The SL was always
ahead of its time technically - even when it was rolling off the
production line for 18 years at a time, as was the case with the SL
bearing the internal code R107 (from 1971 to 1989). Over 650,000 SL
vehicles have left the production halls in Sindelfingen and Bremen since
1954, and from the last model generation alone - which celebrated its
premiere in 2001 - nearly 170,000 specimens found their way into the
hearts of the enthusiasts amongst fans of high-calibre sports cars.
The new generation of the Mercedes-Benz SL-Class now being presented is
the sixth to follow the 1952 racing car. In the unique tradition of the
SL it is entering its era as an athlete, refined aesthete and innovative
trendsetter with an extraordinarily high utility value. Mercedes-Benz
is initially offering the new SL with two engines - as the SL350 with a
V6 engine and as the SL500 with a V8. The new BlueDIRECT engines have an
output of 225 kW (306 hp) in the SL350 and 320 kW (435 hp) in the SL500
(a 12-percent increase over the predecessor).
Moreover, the new Mercedes-Benz SL-Class breathes new life into the
meaning of the famous abbreviation "SL" - super-light - through
systematic weight reduction. For the first time ever, Mercedes-Benz is
implementing an all-aluminium bodyshell in series production. The newly
developed vehicle weights approximately 110 kilograms less than a
comparable bodyshell made of sheet steel. Nevertheless it is even more
rigid - and safer - than its predecessor. Mercedes-Benz has achieved
this through a systematic intelligent material mix of aluminium alloys
and aluminium components which are tailor-made for the respective
requirements, combined with just a few portions of high-strength steel
and magnesium.
Although the new SL is even more comfortable and has more safety devices
on board than its predecessor and therefore does actually sacrifice
some of the weight saved through the aluminium bodyshell, the scales
show some astonishing figures: the new SL500 (1785 kg) weighs around 125
kilograms less than its predecessor. On balance, the SL350 (1685 kg) is
even 140 kilograms lighter - all thanks to a host of other intelligent
enhanced details to reduce weight, which Mercedes-Benz has also
implemented in the new SL in addition to the aluminium bodyshell.
And these measurement results do not just impress as figures on the
page; they are very much perceptible and tangible in practice, too. The
resulting increase in longitudinal and lateral dynamics facilitates
superb performance with a decided passion for cornering. The greater
track width at both the front (+ 38 mm) and rear (+ 77 mm) axle serves
the handling which is at once sporty and agile and keeps the car under
safe control. Drivers will find the new Mercedes-Benz SL-Class even more
agile than its predecessor - sheer pleasure for those of a sporty
orientation.
There are two suspension variants from which to choose. The SL is
supplied as standard with semi-active adjustable damping (lowered by ten
millimetres in the AMG sports package). The active suspension system
ABC (Active Body Control) is available as an optional extra. Unique the
world over, it has been enhanced especially for the new SL.
In keeping with the Mercedes-Benz tradition, the new SL couples its
sharpened athletic profile and agile nimbleness with a luxurious
ambience. Its high-quality equipment and appointments contribute to the
exquisite motoring pleasure that can be experienced every kilometre of
the way. Fine materials, finished with great attention to detail, shape
its style and character. The levels of comfort here - unique in the
segment of luxury sports cars - blend with high everyday practicality,
for the new SL shines with top marks where open-top motoring, suspension
comfort and comfort on long journeys are
concerned - plus its exemplarily low background noise, which is
comparable with that of a saloon. This all adds up to the fact that this
vehicle is a Gran Turismo in the very best sense of the word.
The safest and the most sparing
Thanks to the crash-optimised aluminium structure, standard-fit
PRE-SAFE® and assistance systems on the same high level as the S-Class,
the SL is the world's safest roadster.
What's more, it is the most frugal one in its class. The SL350 consumes
6.9 litres over 100 kilometres, which is virtually 30 percent less than
its predecessor (CO2 159 g/km). The SL500, too, posts a persuasive set
of efficiency figures: 9.1 litres per 100 kilometres (minus 22%)
correspond to 212g/km CO2.
The design, meanwhile, displays all the classic proportions so
characteristic of the SL. Right from the first glance the
masculine-looking roadster with a broad tail end is immediately
identifiable as a member of the current family of sports cars from
Mercedes-Benz. It emphasises its autonomy through a multitude of details
created with loving care.
The sixth generation of the Mercedes-Benz SL-Class also offers a
vario-roof that can be retracted into the boot using an electrohydraulic
mechanism to save space, converting the SL into a roadster or a coupé,
depending on the driver's wishes and the weather. Unlike its
predecessor, three versions are available for the new SL: painted, with a
glass roof or with the unique panoramic vario-roof featuring MAGIC SKY
CONTROL. The transparent roof switches to light or dark at the push of a
button. When light it is virtually transparent, offering an open-air
experience even in cold weather. In its dark state the roof provides
welcome shade and prevents the interior from heating up in bright
sunlight.
With two innovations, the new SL remains true to its tradition as technological trendsetter:
MAGIC VISION CONTROL is a new intelligent, high-efficiency
windscreen wiper/washer system. Its system of channels supplies water to
the windscreen just in front of the laser-cut wiper blade lip. As a
result, when spraying, there are no gushes of water on the windscreen to
disrupt visibility, and yet the windscreen is kept clean.
Also unique, the Frontbass system uses the free spaces in the
aluminium structures in front of the footwell for housing the bass
loudspeakers. As a result, the new SL features clear, crisp bass sounds
that facilitate a concert hall ambience even with the top down.
Both innovations are part of the extensive standard equipment of the new SL.
Design: Masculine, muscular athlete's physique
The design of every Mercedes-Benz SL has an obligation to a great
legend, and yet it is always very clearly looking to the future. The
designers have unmistakably showcased the youngest generation of the
style-defining roadster on the basis of tradition, but also with new
perspectives and visions. This has resulted in a formal identity and the
high overall aesthetic quality.
In the interplay between innovation and tradition we have created a
stylish, sporty and elegant luxury sports car with the classic,
well-balanced hallmark SL proportions: the long bonnet is followed by a
compact, set-back passenger compartment. A broad, muscular, racy-looking
tail end completes the picture.
Design boss Professor Gorden Wagener: "The athletic, sports star's
physique with its masculine, muscular character says a great deal about
the new SL and confidently emphasises its status as the high-performance
heart of our brand. At the same time, discerning athletic standards are
met by powerfully sculpted surfaces formed by just a few lines and
beautifully crafted details. The traditional design elements from our
rich history are more than visual quotations. They tell of the courage
and the pioneering spirit which have shaped our brand, and reflect these
properties in a contemporary way - with enthusiasm and passion.
Alongside top technical performance and innovations, it is also this
which makes the new SL an unmistakable character."
The front signals a self-confident presence
Visually, the new SL is clearly marked out as a prestigious member of
the current Mercedes-Benz sports car family. At first glance this is
evident from the very upright classic sports car radiator grille which
has featured on all the Mercedes-Benz vehicles with a sporty character -
right from the initial generation of the SL. The central star in the
radiator grille points the way to the future: it is a contemporary
reinterpretation of the famous trademark, which now runs into the
centrepiece with organically flowing contours.
What's more, on the new roadster the designers have waived the classic
separation of the bumper and the radiator grille. The lower edge of the
grille now dips into the bumper, supporting the pronounced V-shape and
resulting in more formal presence. In addition to this, the steeply
positioned radiator grille lengthens the bonnet in visual terms. Two air
outlet grilles, each with two chromed fins, have their roots in
Mercedes-Benz's traditional, dynamic design repertoire. A succinctly
sculptured edge - developing from the upright radiator grille - draws
across the long bonnet in a taut arch and flows organically into the
A-pillar.
Dynamically positioned at an angle, headlamps located far on the outside
flank the distinctive front and the broad air intake, giving the new
roadster its own inimitable look. It appears masculine and it does also
radiate a certain restrained aggressiveness.
The standard-specification ILS headlamps are characterised by very
high-quality tubes for the low and main beam which have been styled with
great attention to detail, plus a chrome bracket surrounding the main
headlamp and the flared arrangement of the indicator lamps and
sidelights. All the further functions feature LED technology - such as
the distinctively curved sidelights and the horizontal band of the
daytime running lamps in the outer sections of the bumper.
The silhouette displays muscles with character
A minimal amount of artistically styled lines define the athletic yet
smooth surfaces of the flanks. The shoulderline rises from the headlamps
and stretches like a tensed muscle over the entire length of the
vehicle and into the tail lights. Side grilles with fins in the front
wings stylishly cite the classic SL legend and form the starting point
for a feature line. This structures the proportions and lends the
vehicle a visual forwards thrust even at a standstill. It tapers out in
the tail light as a discreet line.
Free-standing exterior mirrors located on the beltline not only support
the modern character of the side view; thanks to this position they also
improve vision of the road.
Depending on the engine variant, various light-alloy wheels are
available in 17-inch and 18-inch versions. The exquisitely bordered
wheel arches are designed for a maximum size of 19 inches at the front
and 20 inches (only in the case of AMG) at the rear.
Muscular tail end
A small number of sweeping lines shape the broad, clearly defined tail
end. Elegantly flowing and at the same time racy and muscular, it forms
the roadster's distinguished finishing flourish that is so full of
character. Thanks to the boot lid with its steel interior and plastic
panelling, it has been possible to stow the aerials out of sight inside
the vehicle so that they do not interrupt the flowing lines in the rear
area. This is also the case with the roll-over protection, which lies
hidden from view in the body and is only activated in case of danger.
Tail lights with LED High Performance technology highlight the width of
the tail end. They taper inwards to a point and have a discreet kink in
the contour. The rear fog lamp is located centrally between two
trapezoidal exhaust tailpipes. A horizontal swage line in the lower area
of the bumper provides added emphasis of the broad effect.
The colour range for the exterior encompasses twelve different paints.
These include the BRIGHT paint diamond white and the special colour
cerussite grey metallic SHAPE - the first matt paint in the
standard-specification paint range for a Mercedes-Benz model series.
Interior and appointments: Luxurious comfort and sporty precision
The interior of the new SL impresses with its generous amount of space,
high-quality materials, high sense of perceived value and lovingly
crafted details displaying tangible and visible precision.
Compared with its predecessor, the new generation of the SL is much
longer (+ 50 mm to 4612 mm) and wider (+ 57 mm to 1877 mm), providing
more room for more comfort in the interior, too. Shoulder room (+ 37 mm)
and elbow room (+ 28 mm) have been increased, exceeding the dimensions
normally found in this vehicle class. Clear lines create a formally
coherent internal space within this comfortable interior. Perfectly in
tune with the roadster's character, it combines the unpretentious
atmosphere of a high-performance sports car with the comfortable,
stylish ambience you come to expect in a luxurious touring car.
The wrap-around effect has class
In conjunction with the beltlines on the doors and the parcel shelf, the
upper section of the dashboard creates a formal unity and - with the
exception of the black interior - it is always styled in a contrasting
colour. Generously used wood trim extends from the centre console across
the dashboard into the doors, creating a pleasant wrap-around effect.
Three types of wood along with two different aluminium trim finishes are
available (high-gloss brown walnut, satin-finish light brown poplar,
high-gloss black ash), plus two differently treated longitudinal-grain
aluminium trim parts (light or dark). The links between the dashboard,
centre console and door trim panels have been styled so that they are
continuous and they support the wrap-around effect. Minimal gap
dimensions please the eye and represent the high precision with which
the SL is manufactured.
High-quality instruments add emotionally appealing flourishes
In the area of the dashboard, four circular ventilation outlets provide
some striking eye-catching touches. Set in metal, these air vents are
reminiscent of jet engines and are a contemporary, emotively interpreted
way of paying homage to the history of Mercedes-Benz sports cars.
Inside two tubes the sporty instrument cluster boasts classic round
dials with three-dimensional graduated rings, back-lit dials in the
centre of the tachograph and rev counter, plus high-quality needles. In
the centre between the two round dials, a colour display provides
information from the on-board computer and indicates vehicle functions.
The system is operated via a three-spoke sports steering wheel with
shift paddles and twelve function buttons. The steering wheel featuring a
flattened bottom section has an ergonomic grip area and galvanised
spokes, and is covered with nappa leather - in the airbag section, too.
A large COMAND colour display in the centre of the vehicle takes care of
the numerous display functions for the entertainment, communication and
navigation facilities. A particularly eye-catching feature on the
tunnel of the centre console is a new DIRECT SELECT shift lever. Small
and fine, it is a true visual highlight. Like the central rotary knob
for operating the COMAND system, it is optimally positioned from an
ergonomic point of view. Located in front of these controls is the
lidded compartment for the two cup holders.
Spotlight on the stylish ambience
Making dynamism visible is what it's all about where the ambient
lighting in the SL is concerned. The fibre-optic cables with three
colour options to choose from stretch between the beltline and the door
centre panel in one tier over virtually the entire length of the door,
behind the trim on the dashboard and in the front panelling.
Seats with a noble, sporty character
The new Mercedes-Benz SL-Class's fully electric seats with a memory
function meet discerning and wide-ranging standards regarding seating
comfort, ergonomics, safety and sportiness. The ergonomically optimised
seats themselves are more slender than in the predecessor and emphasise
the noble, sporty character. This is underlined in visual terms by
sophisticated stitched seams and by a layout which varies depending on
the choice of leather. Alongside excellent lateral support, the seats
also offer high levels of comfort.
The superstructure of the seat cushion and backrest is formed by a
weight-optimised welded construction of steel and sheet metal panel
parts. This structure also makes a significant contribution towards
transverse support for the sidewall in the event of a lateral collision.
In addition, a thorax-sidebag is installed in the backrest. A newly
developed combination of a sine spring core principle with rubberised
matting and a foam layer as damping ensures support and comfort.
Both the driver and the passenger can adjust their seats precisely
according to their requirements and body measurements. Even in the
standard equipment there are extensive electrical adjustment options
available for doing so, enabling fore-and-aft and height adjustment to
be made just as easily as the seat cushion angle, cushion depth and
backrest angle adjustment. The crash-responsive head restraints are also
adjustable for height. The range of equipment also includes 4-way
lumbar support adjustment - this feature is housed in the centre section
of the backrest cover. The occupants can operate it via the central
control panel and the head unit. Using the memory buttons, the current
seat position can be stored, and on the driver's side this also applies
to the positions of the steering wheel and exterior mirror.
A very attractive solution has been found for convenient access to the
rear compartment for easy loading - in both visual and functional terms.
A button on the shoulder of the backrest operates the backrest lock
electrically and enables the seats to be moved forwards and backwards in
order to create sufficient room to manoeuvre.
Also part of the standard specification is a seat occupancy sensor with
automatic child seat recognition on the front-passenger side - for child
seats with a transponder specially approved for Mercedes-Benz.
For enhancing comfort even further, in the case of the leather
appointments the seats are covered with sun-reflecting leather. This
specially coated leather reflects the heat of the sun and, in particular
where the appointments colours are dark, it reduces the extent to which
the surface heats up. In combination with the optional active
ventilation the thermal seat comfort is tangibly improved.
The following seat variants can be selected as an optional extra:
Luxury heated seats with active seat ventilation: it ensures a
pleasant seating climate. Leather appointments are a prerequisite for
this option
Active multicontour seat package: three air chambers in the lumbar
area can vary the contour of the seats in order to prevent fatigue.
Elongated air chambers in both of the side cushions on the backrest
ensure optimum lateral support
Dynamic multicontour seat: the dynamic multicontour seat is an
enhanced version of the multicontour seat. It automatically adjusts the
lateral structure of the backrest in accordance with the current driving
situation. In order to do this it varies the air pressure in the seat
bolsters on the backrest electropneumatically, depending on the steering
angle, lateral acceleration and speed
Health and comfort-conscious climate
The control panel for the standard-specification luxury automatic
climate control THERMOTRONIC featuring separate temperature adjustment
for the driver and passenger has been redesigned and revised.
Mercedes-Benz has placed particular emphasis on new technologies for
saving energy. They include a window demisting sensor integrated in the
base of the interior mirror. It measures the window temperature and
interior humidity and transmits these data to the climate electronics.
They can use them to determine whether the windscreen has misted up. If
this is not the case, in A/C operation it can continuously adjust the
compressor in the background if no dehumidification is necessary. In
other words: thanks to the sensor, the compressor can be operated as
required, saving drive energy. The A/C function can remain permanently
active. A further advantage is that, as the air conditioning only
dehumidifies and cools as much air as necessary, dry eyes are prevented -
a tangible gain in terms of comfort.
The air conditioning is also linked to the ECO start/stop function and
can therefore also regulate the climate during the stop phases.
So that SL drivers can enjoy an open-air experience even when the
weather is cool, the innovative neck-level heating system AIRSCARF is
available as an optional extra - as was the case with the predecessor.
Warm air flows through a nozzle at the front of the head restraints, and
the system directs it around the head and neck area of the occupants.
Room for luggage and lots of equipment
Suitability for everyday use is a key word which is traditionally taken
extremely seriously at Mercedes-Benz - even in the case of vehicles
designed to be very sporty. This is why the occupants in the new SL will
find plenty of stowage facilities for larger and smaller items alike.
In addition to the glove compartment, the centre console offers three
stowage compartments within easy reach:
One of these is at the front beneath the air-conditioning control
panel, which can be optionally fitted with two cup holders or with an
ashtray and one cup holder
A large stowage compartment beneath the armrest can be used for the
safe storage of a telephone, iPod ® or similar, for example
A centrally located rear box with a retractable luggage cover
completes the range. A bottle holder is fitted here as part of the
standard specification, whilst a fire extinguisher is available as an
optional extra
A lockable rear box behind the driver's seat creates additional stowage
space. Its catch is automatically closed when the vehicle is locked.
In the lower section of the door trim, a long, open door pocket offers
further, easily accessible stowage space. As no bass loudspeakers have
to be fitted in the door thanks to the Frontbass system, Mercedes-Benz
makes sensible use of the space gained here by adding an extra stowage
compartment, which can be used for an umbrella, for instance.
The designers have also thought the details through: smaller but useful
items can be fixed in place by a net on the centre tunnel of the
passenger's footwell.
The design of the boot is largely determined by the vario-roof, which
has to be housed in the upper part of the boot when the roof is open. In
total the new SL offers luggage capacity of up to 504 litres - 364
litres with the roof stowed. There is always room for stowing luggage or
two golf bags without any problems at all, thanks to the optimised boot
design.
A luggage cover which can be adjusted lengthwise with a handle prevents
pieces of luggage from colliding with roof elements in the boot when
opening the roof. Only when the cover is adjusted to the rear can the
vario-roof be opened. Anyone wanting to use the entire boot capacity
when the roof is closed can adjust the cover to the front or remove it
completely.
At the press of a button, the roof elements stowed in the boot can be
tilted upwards by about 25 degrees to make loading and unloading easier -
as was the case in the predecessor (Easy-Pack system).
The compressor and the TIREFIT filler bottle are housed in a stowage
compartment in front of the recess which can be accessed by lifting up
the boot floor.
HANDS-FREE ACCESS - 'kick' to open
One of the new products and features from Mercedes-Benz is a system
known as HANDS-FREE ACCESS, which is included in the KEYLESS-GO package.
It is available on request for the new SL for the first time anywhere
in the world, and it allows drivers to operate the boot lid without
using their hands. This work is taken care of by a hydraulic drive
system, for which the control signals are given by the SL owner without
touching anything, but by making as though to kick the area of the rear
bumper with their foot; doing so activates this fully automatic
comfort-increasing equipment. Mercedes-Benz is the only manufacturer to
offer a system which not only opens but also closes the boot lid
automatically.
With the innovative convenience function HANDS-FREE ACCESS there is no
longer any need for drivers to have to get annoyed by having to put
their purchases and other objects down on the - often dirty - ground
when out shopping and when they literally have their hands full, in
order to reach for the handle. Should an unintentional 'kick' result in
the boot lid opening or closing without the driver wanting this to
happen, a second kick will correct it. When this occurs, the automatic
system interrupts the procedure and reverses the effect of the signal
given in error by actuating the boot lid against the original direction
of movement - in the case of unintended opening, the second kick closes
the boot lid again.
An appropriate safety program facilitates unhindered use of the
HANDS-FREE ACCESS system. An acoustic signal provides the information
that an opening or closing procedure has been initiated, and an
automatic reversing function stops the boot lid as soon as the system
recognises that there is an obstacle blocking the boot lid.
For the HANDS-FREE ACCESS system to be included, the vehicle must be
fitted with KEYLESS-GO - this allows non-contact access to the vehicle
In addition to this the correct KEYLESS-GO vehicle key has to be in the
vicinity of the vehicle, so in order to open the doors it can, for
example, stay in the driver's coat pocket or handbag. In order to
activate the HANDS-FREE ACCESS system for the boot lid, the KEYLESS-GO
key must not be further than 1.5 metres away from the rear end of the
vehicle.
Body and bodyshell: Aluminium comes up trumps
Cars are becoming increasingly safer, more comfortable, but often
heavier as well. The new Mercedes-Benz SL not only stops this trend, it
turns it around. In spite of increased comfort, performance and safety,
it is 140 kilograms lighter than its predecessor.
The greater part of the weight-reduction "diet" is hidden from the eyes
of the observer of the SL. Under the aluminium outer skin there is a
bodyshell made almost entirely from aluminium, only very few components
being made from other materials. The even lighter magnesium is used in
part for the cover behind the tank. The A-pillars and the roof frame are
of steel sheet metal incorporating high-strength steel tubing. For
these elements steel is the best solution to provide survival space for
occupants in the event of the vehicle overturning.
The bodyshell of the Mercedes-Benz SL-Class is the first all-aluminium
bodyshell to be produced in large series at Mercedes-Benz. This entirely
new development weighs 254 kilograms and is thus 110 kilograms lighter
than a comparable steel bodyshell. Further extensive lightweight design
features compensate the additional weight unavoidably caused by the
increased comfort, the new assistance systems and other technical
features. Under the bottom line an enormous weight advantage remains for
the new SL. As the SL500 it weighs 125 kilograms less than its
predecessor, while the SL350 weighs 140 kilograms less than its previous
version. And its preceding model already had a lightweight aluminium
bonnet and doors.
"The effect is rather as if a heavyweight-class passenger had got out of
the car and taken their heavy flight luggage, too" says Dr Thomas
Rudlaff, responsible for the aluminium bodyshell at Mercedes-Benz. "The
result is perceptible and measurable. Less weight means more dynamism
and less consumption. In other words: the motoring enjoyment increases
and the environmental burden decreases."
For the roadster the aluminium bodyshell is superior to a steel construction
The developers at Mercedes-Benz did not rest content achieving weight
benefits alone. The aluminium structure had to be superior to a steel
construction in terms of rigidity and comfort as well. In order to
attain this high objective, developers consistently went for an
intelligent lightweight construction, and explored many new paths to do
this. Every single component of the aluminium bodyshell was specifically
optimised for its particular function and expected loads. Thus, diverse
processes are used to make different kinds of aluminium depending on
the use the component is to be given: the parts are made by chill
casting or vacuum die casting, worked into extruded aluminium sections
or into aluminium plates of thicknesses that vary within one and the
same component; these are what are known as the tailored welded blanks.
Expressed in numbers, the bodyshell weight is made up of: 44 percent
cast aluminium, 17 percent aluminium sections, 28 percent aluminium
sheet metal, 8 percent steel and 3 percent of other materials.
At the Bremen production facilities the parts are assembled using
diverse load-adequate joining methods, some of which are innovative
processes. Secure joints are ensured, for example, by MIG welding,
hemming, bonding, self-piercing rivets, flow hole bolting, or friction
stir welding - a joining method by which a highly resistant weld seam is
produced by means of friction heat; a method particularly well-suited
to aluminium on account of its low melting point.
Particular highlights of the bodyshell:
The firewall is at present the largest aluminium cast component made in large series for vehicle bodywork
Many sheet metal parts are designed in such a way that for the first
time they can be made from 100-percent recycled aluminium, saving 80
percent of the energy used in their production.
The main floorpan consists of a 3-layer shaped panel made from thin,
extrusion-moulded hollow sections, welded together by friction stir
welding.
The longitudinal members in the vehicle front end are made using
high-pressure hydroforming (IHU) technology, which enables the creation
of highly complex and robust components, permitting optimum use of
reduced installation spaces.
The door sills (longitudinal members) consist of 1.7 metre-long,
7-chamber extrusion-moulded aluminium sections; these provide rigidity
in the lateral sectors and safety in the event of a collision. Flexible
chamber distribution makes possible a minimum component weight coupled
with optimum characteristics.
The tunnel is made of aluminium sheet metal with a reinforcement of
varying thickness (3 different thicknesses depending on the sector, a
so-called tailored welded blank, TWB).
The rear sector floor is a MIG welded frame with a hollow chilled
cast longitudinal member as its central element. This technique is
employed in the SL for the very first time in automotive bodyshell
construction.
The rear sector floor frame structure is closed by floor sheet metal panels and the boot tub made by vacuum die-casting.
The boot recess is made from recycled sheet metal.
The central member connects the front end with the rear sector
floor. The mounting points for the drive shaft, the transmission cross
beam, the transmission tunnel braces and the seat bolting points on the
tunnel side are all integrated into a single element. The wall
thicknesses and rib distribution are oriented bionically towards the
requirements and loads.
Many other components were optimised bionically, i.e. based on
examples from the natural environment. These structures reduce the
vehicle weight compared to a classic design even further.
The sum total of all the design measures leads to a lightweight,
torsionally and flexurally rigid bodyshell with an optimum
rigidity/weight ratio. It was possible to increase the bodywork's
torsional rigidity by more than 20 percent over the already highly rigid
preceding model series. This is confirmed by measurements of the new
SL's torsional strength - at 19400 Nm per degree the roadster achieves
an absolute top value (its predecessor already reached 16400 Nm per
degree).
Meets the highest safety standards
At the same time the high-strength structural elements of the aluminium
bodyshell make the new SL even safer than the preceding model in the
event of a collision. Extrusion-moulded sections, connecting cast nodes
and a double-thickness plate floor form a passenger compartment that is
just as lightweight as it is sturdy. Two aluminium sections in each door
together with the side sills (very rigid thanks to their internal
chamber structure) and crash-resistant seats provide the greatest
possible survival space in the event of a side collision.
A front end deformation zone acting on several levels and in which the
aluminium front axle subframe is integrated as an additional third
longitudinal member, distributes collision forces to a large area,
conducting them past the passenger compartment. And in the rear, too,
there is sufficient energy-absorbing deformation potential. A structural
cage made from chilled cast longitudinal members, transversal sections
and a cast magnesium tank separation bulkhead also contribute to this.
This is also where the fuel tank is nested in a crash-protected manner
above the rear axle. This way all the
statutory safety requirements are met as well as the even stricter ones from Mercedes-Benz.
Best marks for NVH comfort
Thanks to its innovative aluminium bodyshell concept, the new SL is also
unique among the roadsters in terms of NVH comfort (noise, vibration,
harshness). One contributing factor towards its optimum vibration and
road roar characteristics is a very rigid connection between the front
section and rear floor, allowing relaxing travel even over long
distances, and at the same time offering impressive driving dynamics.
Although aluminium features a higher sound emission and radiation level
than steel, the new SL is the quietest vehicle in its class.
Mercedes-Benz compensates for the acoustic disadvantages of aluminium by
means of a consistent sound insulation concept with targeted adaptation
of the sound damping materials to each problem zone, and through the
use of innovative sound-insulation materials:
A special firewall damping with variable mass distribution and a significant heavy layer proportion attenuates engine noise.
In conjunction with the plate floor, single-piece, foam-backed
carpeting with virtually no seams reduces the roll noise of the vehicle
in the interior.
A spray-on lining attenuates the structure-borne sound in the vehicle interior and exterior.
Textile wheel arch linings, acoustically absorbing shield plates and
bodyshell foam elements for critical sectors also contribute towards a
smooth ride.
Damping in the rear wall transversal cross member and boot lateral
elements as well as in the forced ventilation openings prevent
disruptive tyre and wind noises from making themselves unpleasantly
noticeable in the vehicle interior.
A further contribution to the good interior acoustics is the laminated
glass windscreen with acoustic film. The transparent, highly resilient
film absorbs the vibrations of the windscreen and reduces the
perceptible sound level in many frequency ranges.
The precision workmanship on the acoustics goes so far as to ensure that
the hydraulic pump for the electrohydraulic vario-roof is encapsulated
and decoupled from the bodyshell. In addition to this, a newly developed
insert nozzle sees to it that the pressure pulsation in the pump is
reduced to a minimum right from the outset. This means that pump noises
are only barely audible for the driver and passenger.
The doors and the bonnet, too, are lightweight
The intelligent material mix is completed by the boot lid, of SMC-hybrid
design (SMC = sheet moulding compound). It consists of a single-shell
synthetic material panel mounted on a steel reinforcement. Both
materials have virtually identical thermal expansion coefficients and
complement each other very well. The interior steel construction permits
maximum rigidity with minimum use of space, while the plastic panelling
allows the full integration of the aerials for navigation, digital
radio and mobile telephony out of sight in the rear area so that the SL
does not need to carry a bothersome aerial stump on its aerodynamically
refined body.
The bonnet of the SL is made from aluminium, as was that of its
predecessor. It was optimised in terms of form and materials,
contributing towards the outstanding pedestrian protection.
The doors, too, are of a lightweight design and made from aluminium.
They are fashioned from a combination of sheet metal, extruded sections
and cast metal parts, joined by diverse methods: riveting, bonding and
hemming. Their aluminium and steel hinges are friction-based and are
infinitely adjustable to any desired angle when opened, so that when
getting into or out of the car they can remain securely open at any
angle permitted by the space available at the side. This is particularly
desirable in cramped parking conditions such as in a garage or car
park.
Unique item of equipment: MAGIC SKY CONTROL
The proven electrohydraulic vario-roof - which turns the roadster into a
closed coupé with a fixed roof in just a few seconds at the push of a
button - has been intelligently enhanced, with Mercedes-Benz continuing
to play the pioneering role here. For the new SL Mercedes-Benz is for
the very first time offering drivers the choice between three variants
of the lightweight-construction vario-roof:
The base version is a roof painted in the vehicle colour
As an alternative, a transparent variant with a roller blind can be selected
The third variant from which drivers can choose is the panoramic
vario-roof with MAGIC SKY CONTROL. This glass roof switches to light or
dark as required at the press of a button. When light it is virtually
transparent, offering an open-air experience even in cold weather. In
its dark state the roof provides welcome shade and prevents the interior
from heating up when the sun's rays are very intense. In other words: a
feel-good atmosphere at the touch of a button
The operating principle is based on the physics of a plate condenser: if
the glass structure is subjected to an electrical voltage, particles in
the structure position themselves so that light is able to pass through
the glass. If the voltage remains switched off, however, the particles
position themselves randomly. This partially blocks the light, and the
glass remains dark. The control unit and converter are integrated into
the front section of the roof, and the switch is in the overhead control
console.
In addition to the unique panoramic effect and transparency at the touch
of a button, MAGIC SKY CONTROL also provides an atmosphere of
wellbeing. UV and infrared light are also effectively blocked in
transparent mode, while insulation increases even more significantly in
the darkened mode, thereby helping to keep the temperature on interior
parts such as armrests cooler by up to ten degrees Celsius compared with
conventional green glass.
Since the innovative glass also shields against the sun's rays far more
effectively than conventional thermal insulation glass or sunblinds, the
occupants of the new Mercedes-Benz SL-Class will also enjoy the highest
level of climatic comfort at the same time. When driving with the roof
open would be unpleasant due to intense heat, the driver and passenger
are able to remain composed under the MAGIC SKY CONTROL roof - making an
important contribution towards driver-fitness safety, a concept which
Mercedes is well known for promoting. Even when the vehicle is at a
standstill the interior does not overheat, since the roof is switched to
darkened mode when powered off.
But MAGIC SKY CONTROL not only benefits the occupants. Some of the
strain is also taken off the air conditioning, thereby saving on CO2
emissions.
The frame of the three roof variants is now made of magnesium. This
makes each roof around six kilograms lighter than in the previous model,
giving the car a lower centre of gravity, and therefore better agility.
The engineers have refined the operating mechanism for the roof and boot
lid. It now takes less than 20 seconds to open or close the roof
completely.
Sophisticated corrosion protection concept
The aluminium bodyshell of the new SL offers no point of attack for
corrosion. A sophisticated surface protection concept ensures the
preservation of the brilliant look both of the outside skin and of the
underside of the sheet metal panels, thus simultaneously protecting the
renowned reliability and value stability of Mercedes-Benz vehicles. The
protection concept was developed and tested on the basis of the
environmental burden in different climate zones of the world and the
specific loads the vehicle is subjected to.
The foundation for maximum corrosion resistance is formed by
corrosion-resistant aluminium alloys and design features, while the few
steel vehicle components are all fully galvanised. High-quality
zinc/nickel coatings or special electrochemical insulation measures
prevent contact corrosion with aluminium. All the seams are meticulously
sealed, the surfaces protected through cathodic dip priming and
multiple coats of paint. Sectors particularly exposed to corrosion are
additionally protected with wax, to ensure that the pristine aspect of
the new car is preserved for a long time.
Intelligent Light System and LED tail lights as standard
The headlamps on the new SL have been enhanced. As part of its standard
specification, the new roadster is equipped with the Intelligent Light
System (ILS) featuring bi-xenon headlamps. A driving direction
indicator, sidelights and the daytime running lamps with LED technology
complete the Intelligent Light System.
The tail lights on the new SL benefit from the advantages offered by the
LED technology. LEDs light up approximately 150 milliseconds faster
than conventional bulbs, plus they have a considerably longer life and
conserve current. In the SL's tail lights, the LEDs also light up with
differing intensity in a targeted manner in certain sections of the tail
lights, depending on the light function. This technology ensures an
unmistakable night design.
Rear reversing lights and rear fog lamps are integrated into the rear
bumper. The third brake light featuring LED technology is integrated in
the boot lid above the Mercedes star.
Lightweight construction under the microscope: Progress in detail
Right from the word go the target was ambitious: the aim was for the new
Mercedes-Benz SL-Class to tip the scales weighing five percent less
than the previous model. Already declared the benchmark, the predecessor
itself was a shining example boasting various lightweight design
measures, even including bonnets made of aluminium. At the same time,
the specifications book prescribed more comfort, more output coupled
with considerably reduced consumption and fewer emissions, plus a more
rigid bodyshell and even more safety. These demands would render the
vehicle heavier and not lighter - that was clear. The experts calculated
a weight increase of at least 75 kilograms.
Only a lightweight construction on a totally new level - which included
all the vehicle components in the equation - could reconcile these
contradictory requirements. In actual fact, the developers at
Mercedes-Benz have succeeded in undercutting the ambitious weight
targets. The new SL500 weighs no less than 125 kilograms less than the
predecessor of the same name. This corresponds to a reduction of 6.5
percent. Meanwhile the SL350 even manages to exceed the high
expectations even further - with its weight saving of 140 kilograms -
equating to 7.7-percent less.
Bodyshell. Converting the entire bodyshell to aluminium cuts its weight
by 24 percent in contrast with a steel bodyshell featuring comparable
properties (a weight saving of 110 kg). Even the upper door hinges
consist of aluminium.
Damping. The switch from absorber foams to sprayable acoustic
compositions with variable layer thicknesses which can be shaped
according to requirements, plus modified underbody panelling, results in
weight savings in the order of 2.5 kg.
The guide rails for the window lift mechanisms are now comprised of
aluminium instead of steel, amounting to a weight saving of 0.5 kg.
Vario-roof in magnesium/plastic design.The front part of the roof and
the C-pillar are produced in magnesium/plastic, plus there are
additional optimisation measures regarding the design of the tubular
frame, rear shelf, rear window frame and roof frame. The weight
reduction amounts to 15 kg.
Glazing. The windscreen is 0.5 millimetres thinner, with an acoustic film. The weight reduction amounts to over 1 kg.
The rear windscreen is 0.7 millimetres thinner, resulting in approximately 1 kg less weight.
Interior. The dashboard mount consists of a continuous IHP aluminium
tube with magnesium struts and moulded-on polymer brackets. The weight
reduction is 2.2 kg.
With the introduction of shift-by-wire technology, the large shift lever
has been replaced by a joystick-like lever. This DIRECT SELECT
gearshift system weighs only one sixth as much as the automatic selector
lever used in the preceding model. The weight saving is 1.4 kg.
The boot floor is in the form of a polyurethane honeycomb plate instead
of the wood plate previously used. The passenger's foot plate has been
switched over to plastic from steel, saving 1.5 kg in weight.
Seat. New seat structure with new adjustment motors, but a standard-fit
4-way lumbar support and crash-responsive head restraint. Weight
savings: 11 kg.
Electrics. Thanks to an intelligent dynamic load management system, two
batteries are no longer necessary; one 95 Ah battery in the boot is
sufficient, supported by a 12 Ah battery for the ECO start/stop
function. Weight savings: approx. 4 kg.
Every vehicle is given a customer-specific wiring harness for the
interior, cockpit and engine compartment. Thanks to this tailor-made
cable harness, additional weight in the form of wires which are surplus
to requirements can be saved - to the tune of up to 0.4 kg.
The innovative Frontbass system avoids the need for a separate woofer and door loudspeaker. Weight reduction: over 4 kg.
Axles. The four-link front axle had already undergone extensive weight
optimisation for the preceding model, featuring steering knuckles and
spring links made of aluminium. The two front-axle halves now consist
entirely of this material. The integral support frame for the front-axle
halves, steering gear and engine is also produced in aluminium. Total
weight savings: 11 kg.
The rear-axle subframe consists of high-strength steel with adapted
panel thicknesses. It has been optimised in accordance with the specific
engine line-up for the SL350, resulting in a weight reduction of 2.6 kg
over the SL500.
Suspension, Damping. The standard-specification semi-active adjustable
damping in the SL350 is lighter than the standard suspension system,
saving 10 kg in weight.
Brakes and pedals. Optimised brake cooling eliminates the need for large
and thus heavy brake discs on the front axle. Weight savings: 3.8 kg.
Lightweight wheels. New standard-fit lightweight wheels for the SL500
are around 15 percent lighter than cast wheels. Weight saving: approx. 4
kg
Wheel bolts with a weight-optimised head. Weight saving: approx. ¼ kg.
MAGIC VISION CONTROL adaptive windscreen washing system: Visibility as if by magic
An astonishing experience: the wiper blade glides over the badly soiled
windscreen of the new SL, without a sign of a cleaning water jet, the
occupants do not notice anything yet the windscreen is still cleaned!
The new SL is the first vehicle to be equipped with the adaptive MAGIC
VISION CONTROL wiper/washer system developed by Mercedes-Benz. It cleans
the windscreen without the splash of water that usually briefly
disrupts the driver's field of view in the case of conventional
windscreen washing systems - something that is especially unpleasant at
night or when the sun is low in the sky and at high speeds.
In fact, the windscreen cleaning operation in the Mercedes-Benz SL-Class
is still performed with washer fluid in the conventional manner. The
innovation lies in the way the fluid is conducted to the windscreen in
order to clean it. This is done by means of water guides integrated on
both sides along the wiper blade - one on the left and one on the right -
with minute laser-cut spraying holes. Via these channels, the
innovative washer/wiper system always supplies washing fluid to the
windscreen discreetly, precisely where it is needed: just in front of
the wiper blade lip, according to the direction of movement of the
wiper. The holes are distributed along the entire length of the wiper
blade, being more closely spaced towards the outside of the blade, where
it sweeps a greater area, than closer in, where the area swept is
smaller.
Programs for summer, winter and cabriolet operation
Mercedes-Benz controls the MAGIC VISION CONTROL system intelligently via
three partly autonomous wash programs - for summer, for winter and for
cabriolet driving. It is the first windscreen wipe/wash system anywhere
in the world to operate in this way. In summer, small quantities of
water are sufficient to remove a light powdering of dust. In winter the
dirt mixed with de-icing salt requires a greater amount of water. The
MAGIC VISION CONTROL system works in accordance with the outside
temperature, and it also automatically adapts the washer fluid quantity
to the surrounding conditions.
A particularly interesting feature of the SL Roadster is the Cabriolet
function: when the hardtop is down, the electronic control system
reduces the amount of water, apart from which it demands the required
water mainly on the downward stroke of the wiper arm. This way the
windscreen can be conveniently cleaned during the journey and with an
open roof, without any of the water spraying into the vehicle interior.
Another pleasant side effect is that, since the washer fluid is directed
specifically and in a well-metered manner to the area to be cleaned,
one doesn't douse anyone else in the surroundings with water, either,
and it also doesn't distribute any spray onto the vehicles behind. At
the end of the day, a better cleaning effect is attained with up to half
the amount of washer fluid. It has therefore been possible to reduce
the volume of the washer fluid reservoir by 1.7 litres compared with the
preceding model. This in turn contributes to a reduction in weight and
consequently to greater efficiency.
Winter-proof thanks to the heated system
On request the MAGIC VISION CONTROL wiper blades are completely heated
on the new SL, making Mercedes-Benz the first manufacturer in the world
to offer a fully heated wiper/washer system. It consists of a washer
fluid container heated through coolant waste heat, electric heating for
the entire hose system and, as a newly-developed highlight, a fully
heated wiper blade. This effectively prevents the formation of snow on
the wiper blades, so typical in winter. To do this each of the spring
rails of the blade is equipped with a heater foil with an output of 35
watts per blade. It heats the spoiler and the wipe lip. Snow and ice
cannot freeze onto the blade; it remains supple in winter, too, and
always cleans well.
The heating is also controlled as required according to the duration of
operation and the outside temperature. It is only below a temperature of
minus 20 degrees Celsius that the system makes use of the entire
system's maximum output, 270 watts. Between 5 degrees above and 20
degrees below zero the heating operates in an energy-saving mode and
only requires the output needed to thaw out the wiper/washer system and
keep it free of snow and ice.
Aerodynamics: Breezy, but never bothersome
Open-top motoring should be nothing but sheer pleasure: smelling the
forests and meadows, hearing the birds singing, savouring the sound of
the sea, feeling the warmth of the sun. And in spite of this proximity
to the natural world, the occupants in the new SL do not have to
relinquish comfort. Even at higher speeds they are largely unaffected by
any strong winds. In this respect, just like its predecessor, the new
luxury roadster is unsurpassed by no other open-top two-seater.
First and foremost it is the rigid aluminium bodyshell and - one of the
brand's hallmarks - sophisticated aerodynamics which ensure excellent
comfort during open-top motoring. The designers' intelligent and highly
efficient work has resulted in superb aerodynamic properties for the SL
in several respects. This means that the roadster earns top marks in no
less than four important disciplines within its segment:
Best cd figure
Wind noise on a par with a saloon
Open-top motoring in maximum comfort
Best anti-soiling measures
Top-class: cd figure
The new SL shines with a cd figure of 0.27 (in the SL350). Never before
has a vehicle in the roadster segment achieved such a low cd. At the
same time, the cLR value (the coefficient of lift at the rear axle),
which is decisive when it comes to braking stability, is reduced by
0.01. This ensures a lower lift at the rear axle than at the front axle -
which is important for comfortable, safe handling at high speeds and/or
when there is a crosswind.
The fact that not only could the cd figure be cut to a record low but
that it was also possible to reduce the wind resistance as a whole is
even more astounding when taking into account the fact that the new SL's
frontal area is around four percent larger than that of its predecessor
- due in part to its wider track. The product of the frontal area and
the cd figure is, however, smaller.
Alongside a great deal of precision work, some of the other factors which contribute towards the low cd figure are:
a complete engine compartment and underbody panelling concept,
a spoiler lip on the top face of the boot lid,
a specifically designed spoiler lip on the tail light,
wheel spoilers in front of the front and rear wheels, and
redesigned exterior mirrors positioned on the beltline and with a mirror base specially optimised for the new SL.
A newly developed aero wheel which is part of the standard specification
for the SL350 also significantly reduces the wind resistance. Its rim
section is largely closed, which means that the air flowing through the
wheel to the exterior disturbs the air flowing past at the outside of
the wheel than is the case with a conventional wheel. Together with
tyres which have been specially tuned to this end, the aero wheel cuts
the frontal area - which is also a decisive factor in determining the
wind resistance - by 0.01 square metres. This pays off in the form of a
reduction in consumption, which results in one gram per kilometre fewer
carbon dioxide emissions.
In order to minimise wind resistance even further, the six-cylinder
version of the new SL also employs an adjustable radiator shutter. This
consists of a large number of louvres and is positioned between the
radiator and the radiator fan. An actuator fixed to the engine's cooling
module can be turned to close or open the flow path of the cooling air.
In this way the flow of air through the radiator and through the engine
compartment can be regulated as necessary. This means that if the
engine has low-level cooling requirements, the wind resistance falls, as
do the fuel consumption and emissions.
Top-class: wind noise on a par with that in a saloon
Where wind noise is concerned, the predecessor of the new SL was already
the benchmark in its segment. But its successor surpasses this high
level. It is even possible to hold a conversation, listen to the radio
and make a telephone call at high speeds. This is thanks in part to the
new stand for the exterior mirror. Its shape facilitates optimum flow;
both when the inflow is straight and in the case of crosswinds it causes
only low wind noise.
The windscreen fitted with multi-layer foil also contributes towards the
exemplarily low interior noise, combining a low component weight with
good acoustic properties. Low-frequency sounds which can arise through
vibrations in the vehicle's bodyshell can to a large extent be prevented
by the new SL's aluminium bodyshell, through design measures which were
taken into account and tested at an early stage.
Top-class: maintaining a draught-free interior
Even at speeds of around 200 km/h the new SL offers extraordinarily high
comfort during open-top motoring, setting new standards here. When the
vario-roof is closed and the side windows are lowered, a welcome breeze
can be felt during hot weather. Even putting the side windows up
tangibly reduces it. The occupants in the new SL enjoy a comfortable and
virtually draught-free ride as soon as they use a draught-stop. A
conventional, manually operated folding-frame draught-stop comes as part
of the standard specification. Covered with a finely meshed, synthetic
textile fabric, this draught-stop is mounted behind the seats and folded
up by hand. It covers the entire area behind the seat backrests as far
as the upper edge of the head restraints. It can be taken off and stowed
in the boot as necessary.
A highlight comes in the form of a new electrically operated
draught-stop which is available as an optional extra. This new
development can also be extended and retracted by the driver or
passenger during the journey, via a switch in the centre console. If the
switch is operated, a trapezoidal frame is unfolded electrically, and
when it reaches its final position a finely meshed textile fabric covers
it, thus keeping the area behind the occupants virtually free of
draughts. Once it has been retracted, the frame disappears completely in
the rear compartment trim cover.
The innovative neck-level heating system AIRSCARF is also available as
an optional extra. It emits preheated air from an orifice in the head
restraint, and this warm air then wraps itself around the neck area of
the occupants like an invisible scarf, therefore even making it possible
to have the roof open when the temperature is cool, without any serious
inconvenience.
Top-class: anti-soiling measures
Clean exterior mirrors and side windows are important factors where
safety is concerned, yet all too often drivers cannot take them for
granted. In this respect, the new SL profits from the detailed work
carried out by the aerodynamics engineers and can to a large extent
ensure clear vision for drivers - even when it is raining. This is
achieved mainly through a precisely tuned package of anti-soiling
measures. The A-pillar trim with a new shape features an aerodynamically
and aeroacoustically tuned front edge and a water guide channel on the
top edge prevent water from flowing from the windscreen to the side
windows. The new exterior mirror has also been optimised for journeys
during rainy weather. Water guide runnels and additional drip edges have
been integrated into its housing, and to a large extent they keep water
away from the mirror glass, and shift the break-away point of the
droplets to the outside. As a consequence of the aerodynamic measures
the side windows soil only slightly.
Engine and drive system: The power and the economy
Rich power reserves plus modest fuel consumption - this formula
describes the fundamental characteristics of the new SL models. They owe
this in part to the two V6 and V8 units from the new generation of
BlueDIRECT engines from Mercedes-Benz. As is already the case with the
S-Class and the CLS, they now also enable the SL to achieve previously
unattained marks for efficiency in its segment. The V8 in the new SL500
has at its disposal 4663 cubic centimetres of displacement from which it
achieves 320 kW (435 hp) - so in spite of having around 0.8 litres less
displacement that's some 12 percent more than its predecessor (285
kW/388 hp). The consumption, meanwhile, falls by up to 22 percent, with
the torque increasing at the same time from 530 Nm to 700 Nm - an
increase of 32 percent. The V6 engine for the SL350 has the same
displacement as its predecessor - 3499 cubic centimetres - from which it
now achieves 225 kW (306 hp). Whilst this means that its output is 7 kW
less than the engine in its predecessor (232 kW/315 hp), as the torque
simultaneously climbs from 360 Nm to the current figure of 370 Nm, there
is no perceptible loss of power - on the contrary, in fact: when
accelerating, the new SL350 even proves superior. Plus the new V6
impresses with its outstanding consumption figures. It is content with
6.8 litres over 100 kilometres, making it almost 30 percent more
economical than its predecessor (9.7 l/100 km).
Thanks to the economy of both engines, it has been possible to decrease
the volume of the fuel tank from 80 litres to 65 litres. Nevertheless a
greater range is available than was the case with the predecessor.
Of a torquey disposition when sprinting
The acceleration times from 0 to 100 km/h go to prove that economy does
nothing to dampen torquey spirits. Despite a nominal reduction of 7 kW,
the SL350 covers this sprint in 5.9 seconds, which is three tenths
faster than its predecessor. From a standstill the SL500 races to the
100 km/h mark in 4.6 seconds, making it eight tenths faster than the
previous SL500.
Both engines are exemplary when it comes to in-gear acceleration, too.
Proof positive can be found in acceleration from 80 to 120 km/h in 4th
gear, for only good figures facilitate fast and safe overtaking on rural
roads. 5.5 seconds for the SL350 and 3.2 seconds for the SL500 make the
new SL's excellent characteristics in this discipline plain for all to
behold.
"The new BlueDIRECT engines in the SL with six and eight cylinders form a
unique synthesis of effortlessly superior power delivery, comfort and
consuption", comments Professor Dr Thomas Weber, responsible for
corporate research and development at Mercedes-Benz Cars on the Board of
Management of Daimler AG. "Both impress in the new SL, delivering
refinement of the highest calibre and exemplary environmental
acceptability."
The V8 is in a new league of its own
The new V8 was systematically enhanced on the basis of the very
successful predecessor. Mercedes-Benz engineers primarily achieved a
high output for a lower displacement by using one turbocharger for each
bank of cylinders. The turbochargers were configured to provide high
torque even at low engine speeds - compared to the previous engine, the
result is an increase of more than 40 percent at 2000 rpm. A superb 700
Nm are available between 1600 and 4750 rpm.
The V6 impresses with its low fuel consumption and high comfort
The new six-cylinder is a naturally aspirated engine. The most striking
change between the new V6 unit and its predecessor is a reduction in the
V-angle between the cylinder banks from 90 degrees to 60 degrees. This
enabled the balancer shaft counteracting primary vibrations to be
omitted, and as a result the driver registers an outstanding level of
comfort.
Innovative technology makes V6 and V8 engines fit for the future
Both the new V6 and the new V8 from Mercedes-Benz are derived from their
predecessors. They have aluminium crankcases, pistons and cylinder
heads. The crankshaft, connecting rods and valves are of special forged
steel. Practically all the details were, however, newly developed or
revised with the aim of achieving more fuel economy, more output and
more refinement.
The technology package in the new engine generation includes a number of new developments that are unique in this combination:
In combination with multi-spark ignition, a further developed,
3rd-generation direct fuel injection system with spray-guided combustion
and piezo-electric injectors offers further possibilities for fuel
savings - in the V8 by means of an improved, homogeneous combustion
process, and in the V6 by a new, stratified combustion process with a
considerably extended characteristic map and fuel-efficient lean-burn
technology.
In conjunction with the ECO start/stop function, shift point
adjustment and systematic friction-reducing measures, improvements in
day-to-day fuel consumption of up to 30 percent are possible.
Power consumption by ancillary units has been reduced. These include
an optimised water pump with 2nd-generation thermal management, a
demand-controlled oil pump, a volume-controlled high-pressure fuel pump
and an intelligent generator management system.
ECO start/stop function with direct-start
The standard-specification ECO start/stop function operates with
starter-supported direct-start. This means that when the engine is
switched off, the attitude of the crankshaft is registered by a new
crankshaft sensor so that the engine control unit knows the positions of
the individual pistons. On restarting, it can then select the cylinder
that is in the most suitable position for first ignition. After the
starter has briefly turned over the engine, reliable injection, ignition
and combustion is immediately possible there.
An additional, demand-controlled electric transmission oil pump supplies
the clutches of the automatic transmission with oil pressure prior to
starting, so as to enable a swift resumption of the journey after direct
starting of the combustion engine via the ECO start/stop function. The
starter motor (starter) has also undergone thorough modification: it is
now designed to be highly durable, ensuring that it will last a car's
lifetime in continuous urban driving involving frequent auto-starting.
In addition, the on-board electrical system is supported by a second
battery. As is the case with the starter battery (95 Ah), the "auxiliary
battery" (12 Ah) also features maintenance-free AGM technology (AGM =
absorbed glass mat).
Intelligent alternator management
Its intelligent alternator management also contributes to the luxury
roadster's sensitive treatment of energy. When the battery is charged to
more than 80 percent, the alternator is governed to take load off the
engine. The energy required in this operating state is supplied by the
battery. If the driver removes their foot from the accelerator pedal or
applies the brakes, kinetic energy is recovered and fed to the battery.
Automatic transmission for less consumption and more fun at the wheel
All Mercedes-Benz SL-Class models come with the 7G-TRONIC PLUS automatic
transmission as standard. Now in its sixth generation, the multi-ratio
automatic transmission was developed by Mercedes-Benz and has been
produced since 1960. The new version has once again been thoroughly
revised to optimise consumption and comfort compared with its
predecessor. The new generation of the torque converter provides an
improved dynamic response and reduced noise and vibration levels thanks
to a new hydraulic circuit, as well as enhanced dampers and an optimised
torque converter housing. The extreme wheel-slip reduction of the
torque converter housing, combined with
larger mechanical damper de-coupling, helps to reduce consumption significantly;
in addition, the gearshift program in ECO mode has been changed in favour of lower engine rpm at cruising speeds;
friction-optimised bearings and seals plus a new automatic
transmission oil (FE-ATF) with reduced viscosity in conjunction with an
optimised additive package.
This results in more driving enjoyment than was the case with the
predecessor transmission - and also improved smoothness, not to mention
an average of seven percent less consumption (in the NEDC).
What's more, the increased durability of the new oil also brings with it
new oil-change intervals from 50,000 (old) to 125,000 kilometres (new).
DIRECT SELECT gearshift with designer chic and athletic allure
Mercedes-Benz is equipping the new SL with the newly developed DIRECT
SELECT gearshift in the centre console - the first vehicle with an
automatic transmission to receive this honour. In so doing, the premium
brand is establishing a completely new generation of central gearshift
for vehicles featuring shift-by-wire (ShW) transmission technology. Its
small control lever, reminiscent of a high-calibre joystick, has a
driver-oriented position, being installed on the centre console. Its
striking design not only underlines the sporty character of the
roadster; it also emphasises the high quality of the SL with its
exquisite touch and feel, superb ergonomics and unique look.
In addition to an Eco program, the 7G-TRONIC PLUS in the new SL also
offers a sports-oriented automatic program. Over and above this, the
driver can also select a manual shift program which they operate via the
paddles on the steering wheel - which also come as part of the standard
specification.
The two automatic programs automatically adjust on a continuous basis in
line with the driver's behaviour. By way of example, if they step on
the accelerator pedal more dynamically than before, the shift points
automatically move towards more sportiness. In the ECO mode, the shift
program is configured differently for lower engine speeds during
cruising, thus saving fuel.
In the sportily oriented automatic program, the output is available more
spontaneously and it shifts faster. The double-declutching function and
active downshifts have been systematically enhanced. During heavy
braking, the transmission shifts down considerably earlier, so higher
engine speeds make the acceleration which follows easier. The
double-declutching function, in which the engine speed is actively
raised with an abrupt acceleration, ensures faster and more comfortable
downshifting. The concomitant acoustic response underlines a sporty
driving style and enhances the unique roadster feel.
In the manual transmission mode controlled using shift paddles on the
steering wheel, the engine responds to the throttle over a steeper
characteristic pedal curve. Selecting the gear via the steering-wheel
gearshift buttons facilitates minimal shift times and emphasises the
sporty double declutching. In manual mode, the gear indicator in the
instrument cluster moves to a separate section of the colour display,
where it shows the seven available gears plus the gear currently
selected.
Chassis and suspension: Best contact with the road
Powerful when accelerating, effortlessly superior at every speed, zappy
on winding stretches - the new SL is a shining example, displaying
perfect manners on all the world's roads and in all driving situations.
What's more, it also pampers all the senses with any amount of fun at
the wheel. For these emotive experiences SL drivers can thank the potent
engines - and above all the sporty, agile tuning of the suspension -
which is nevertheless very comfortable, being offered in the form of two
different systems for the SL:
The Mercedes-Benz SL-Class features semi-active adjustable damping as
standard. The optional active suspension system ABC (Active Body
Control) is offered as an alternative.
The spring struts which come as part of the standard equipment combine a
steel spring with a continuously adjustable damper. Its damping
properties can be varied via an electrically controlled valve.
Continuous adjustment of the damping in accordance with the respective
driving situation is taken care of fully automatically by control
electronics which record the driving condition in question via sensors.
The control unit uses the sensor data to determine the necessary damping
forces for optimum comfort and handling. On this basis it steplessly
regulates the damping valves at every wheel within a broad damping
characteristic so that sprung mass vibrations such as lifting, rolling
and pitching are minimised on uneven roads. As a result, the new SL
gives its occupants a smooth ride even on poor roads, without
relinquishing any driving dynamics.
The semi-active adjustable damping also rapidly counteracts sprung mass
vibrations caused by the driver, by adjusting the damping
characteristics. By way of example, the dynamic anti-roll and anti-pitch
support compensates for pitch ensuing from braking and accelerating,
and quickly and effectively stems rolling motion which is initiated
above all by cornering or jerking the steering wheel during a dynamic
evasive manoeuvre. Torsion bars at the front and rear axle help to
reduce wide roll angles when cornering, and positively influence the
understeer/oversteer characteristics.
Setting the basic characteristics of the suspension is still left to the
driver, however, using a switch that enables them to choose from a
broad spectrum ranging from comfortable to sporty damping
characteristics. At the touch of a button they can therefore have a
chassis and suspension set-up available which places more emphasis on
comfort, for instance, whilst if they choose the sports setting, they
are opting for a driving experience with a very high level of dynamic
response.
Sports suspension in the AMG Sports package
A variant of this suspension is offered in the AMG Sports package. This
sports suspension lowers the roadster by ten millimetres, the spring
strut and torsion bars are configured to be ten percent more rigid and
the parameterisation of the adjustable damping is selected in such a way
that the sprung mass vibration is dampened more strongly - all measures
which underline the vehicle's sporty character.
ABC suspension for high levels of comfort
As an option the new Mercedes SL is available with the unique active
suspension system ABC (Active Body Control) as an alternative. It has
been further improved for the new SL by the Mercedes-Benz chassis and
suspension specialists. This system's highly effective control elements
are spring struts with a hydraulic steel cylinder arranged in line with
the steel spring. When this cylinder retracts and extends, it actively
adjusts the length of the spring and therefore the spring force in the
spring strut. This eliminates the need for torsion bars at the front and
rear axle.
With this technology an automatically controlled electronic system
permanently adjusts the suspension to suit the driving situation and the
road condition without any perceptible delay. This means that the
active suspension system ABC can raise comfort to a high level, whilst
simultaneously improving the roadster's driving dynamics. This is
possible as it almost completely compensates the vehicle body's rolling
and pitching movements when accelerating, braking and cornering. In
addition to this, at the touch of a button it offers a unique, further
increased spread of suspension settings between sports and comfort.
As the vibrations initiated by irregularities in the road surface are
greatly reduced, the occupants in the SL experience a vehicle with
perfect absorption capacity on poor roads. Above all it is alternating
sprung mass vibrations ("cross-pitching") which are extremely minimal.
Sprung mass vibrations which arise through the driver's influence are
also almost entirely ironed out - this is the case, for instance, when
the body rolls during steering or when there is pitching during braking
and accelerating. The occupants experience a vehicle which drives "as if
on rails", but without having to pay for this with the usual reduction
in ride comfort which is typical of sports suspensions.
As the ABC system modifies the roll torque distribution depending on the
driving speed, the driver experiences handling which changes with the
driving speed. It varies from motoring pleasure where one can afford it
in driving dynamics terms to directional stability where it is most
needed. In other words, on winding rural roads the roadster moves with
nimble agility, and on motorway stretches it stays safely on track and
does not worry the driver with any nervous reactions.
The ABC system is also fitted with a hydraulic all-round level control
system, thus ensuring a constant vehicle level irrespective of the load.
When the engine is running, the driver can raise the level of the
vehicle at the touch of a button, both when the vehicle is at a
standstill and during the journey. Thanks to a new feature in the SL, if
the level is raised by 50 millimetres in this way, the ground clearance
for rough roads or ramps is increased. In addition, the SL fitted with
ABC is automatically lowered by up to 13 millimetres at high speeds,
thus lowering the centre of gravity and wind resistance - and therefore
also the fuel consumption.
More track, less unsprung weight
The track and wheel suspension are the same in the case of both
suspension variants. In favour of sporty, agile and handling which can
be safely kept under control, the new Mercedes-Benz SL-Class has a
considerably wider track than the predecessor (front axle plus 38 mm,
rear axle plus 63 mm).
At the front axle, the tried-and-trusted principle of the 4-link front
suspension has been adopted from the previous model series. It achieved
superb results where comfort, dynamism, agility plus active and passive
safety are concerned. Most importantly they are characterised by two
individual links (a torque strut and a spring link), which are included
in place of a lower wishbone. In conjunction with the ABC suspension no
torsion bar is necessary.
In order to optimise the front axle even further in terms of weight, in
the new SL the steering knuckle and the spring link are also made of
aluminium. The lower front axle elements, the steering gear and the
engine mounts are linked with an aluminium assembly carrier which is
directly bolted to the body.
A lightweight construction was also systematically implemented at the
rear axle, too. In order to reduce the unsprung masses, virtually all
the suspension parts are made of aluminium, as is the subframe with
load-matched panel thicknesses. The weight-reduced rear axle carrier
consists of high-strength steel.
But the focus was not just on saving weight when developing the rear
axle; the engineers have also optimised the kinematics and
elastokinematics, with the objective of achieving more agility. Other
results of the new configuration are lower forces, which considerably
increases comfort. An additional support linking the rear subframe
bearing to the bodywork also has a positive effect on the new SL's ride
comfort. It increases the introduction rigidity - a parameter whose
properties include excellent road roar characteristics where NVH (noise,
vibration, harshness) qualities are concerned. Thanks to these
constructive measures relating to materials technology, the new luxury
roadster offers a chassis with outstanding comfort coupled with
excellent driving dynamics.
Like its predecessor, the new SL with adjustable damping also has an
anti-roll bar, which is mounted directly at the rear axle and assembled
together with the subframe, and serves to reduce the connection points
with the bodyshell.
The chassis has a virtually neutral configuration, pleasing sporty
drivers. In particular in the range from 60 to 130 km/h it reacts with
enormous agility, and therefore facilitates a great deal of fun at the
wheel on rural roads. In so doing the SL allows lateral accelerations
which are impressive even for a sports car. Two different programs can
be selected for the ESP®. The control interventions from the more
sportily tuned variant allow side-slip angles during accelerated
cornering - offering adept drivers plenty of motoring pleasure. At the
same time it can be driven more easily and safely at higher speeds.
Electric Direct-Steer system for more driving dynamics
The broad spread of suspension settings is supported by a new
electromechanical Direct-Steer system with speed-sensitive steering
power assistance and a variable steering ratio that changes according to
the steering angle. The ratio is very indirect when the steering is
centred, which ensures good straight-line stability and therefore a high
level of safety. In contrast to other variable steering systems, the
ratio of the Direct-Steer system decreases rapidly after a steering
angle of 5 degrees, becoming extremely direct from a steering angle of
just 100 degrees. Only relatively small steering movements are then
needed to make course corrections.
In contrast to the predecessor, the Direct-Steer system optimises the
ratio course. This enables the new SL to shine with yet more agility,
making cornering even more fun as a result. At the same time, through
the new ratio course the maximum steering effort required when parking
or turning is reduced by about 15 percent. This means that only 2.2
turns of the steering wheel from limit to limit are now necessary.
This has the following effect in practice: even at urban driving speeds,
the driver needs to perform less pronounced steering movements, making
changes in direction possible more rapidly and with less effort. The
effect of the Direct-Steer system is even more impressive on winding
country roads, where only small steering movements are sufficient to
steer the vehicle. Even on tighter bends, the driver's hands hardly need
to change their grip on the steering wheel. Rapid sequences of bends
can be mastered safely and precisely, and with enormous enjoyment.
Despite its remarkable effect, the key component of the Direct-Steer
system is a simple steering rack. Its secret lies in the teeth cut into
it. In the mid-area these are slightly wave-shaped, with varying flank
profiles. To both sides the teeth are spaced at varying distances apart.
The change in steering ratio is therefore produced by purely mechanical
means. With this ingenious solution, Mercedes engineers have been able
to dispense with the elaborate actuators and complex sensor systems used
by other variable steering systems. The advantages of the Direct-Steer
system therefore include very low susceptibility to faults and low
weight. Moreover, the system always responds predictably and in the same
way at each steering angle, while other variable steering systems
sometimes require rapid adaptation by the driver in rapidly changing
situations.
Instead of hydraulically, as is the case with the familiar
speed-sensitive steering from Mercedes-Benz, the Direct-Steer system in
the SL regulates the steering force electrically. This is taken care of
by an electric motor - positioned axially parallel to the toothed rack -
which transfers its power to the ball screw as a rotary movement via a
toothed belt. The electric motor, drive unit, control unit and sensor
system are integrated in a compact unit.
The control unit evaluates a large number of input variables in order to
configure the steering torque optimally in accordance with the
situation in question. A torque sensor determines the necessary
assistance required at the steering-gear input shaft. In so doing the
electronics take into account, for example, different vehicle axle
loads. Due to the different engine weights, the characteristic maps for
six-cylinder and eight-cylinder models are proof positive of the
engineering artistry that lies behind the system.
Further advantages of the electric steering:
More active response: the electronics support the steering return,
meaning that drivers hardly need to steer in order to return to the
centre position.
Lower consumption: as output is only called up when the driver is
actually steering, the consumption falls by up to 0.3 l/100 km compared
with the hydraulic Direct-Steer system.
Active parking: with the electromechanical Direct-Steer system the
Automatic Parking Control (APC) system can be offered in the
Mercedes-Benz SL-Class for the first time.
Assistance for critical road surface conditions
A further assistance function has been realised in the new SL thanks to
the electromechanical steering power assistance - the Steer Assist
system: it can support stabilisation of the vehicle if the vehicle
brakes on a road surface with different friction (µ-split) on the left
and right, making it pull to one side. Drivers can find themselves
confronted with this situation, for example, on a road surface which is
covered with ice on one side. When braking, the vehicle then turns in
the direction of the high friction - referred to by experts as a yaw
impulse.
In this case the steering assistance system indicates to the driver via
the steering wheel that they should countersteer in the correct
direction in order to compensate for the yaw impulse caused by the
difference in friction - until the vehicle has stabilised again. In
order to do this the control unit evaluates the difference between the
ABS pressures on the right and left, giving an indication of different
road surface friction coefficients, and it also includes the ESP® data
which register oversteer in this sort of situation.
By way of indication, the electric steering power assistance impresses a
steering torque which supports the driver's own reaction like a
suggestion. This steering torque, which causes the driver to steer
correctly through a light impulse, is hardly perceptible, and most of
the time it is not even noticed at all. Nevertheless the assistance
function is effective. However the steering assistance system merely
provides an indication of the direction in which the driver should steer
in order to stabilise the vehicle; it does not overrule the driver.
Brakes for sporty driving enjoyment
The new SL has adopted the proven braking system with a dual-circuit
brake and the split of the two braking circuits between the front and
rear axle from the predecessor model. At the front all the variants are
equipped with newly developed 4-piston fixed-calibre brakes with an
aluminium monobloc design and perforated brake discs. 1-piston combined
floating brake callipers are fitted at the rear.
In order to be able to provide the required output from the braking
system, the heat arising at the brakes must be removed as quickly as
possible. This is why special attention was given to aerodynamically
favourable and highly effective brake cooling. On the basis of different
wind tunnel and road tests, the aerodynamics engineers developed a
system comprising several components for targeted air ducting in the
front axle area. A brake air channel has been integrated into the front
engine compartment trim in order to guide the air over the front wheel
spoiler in a targeted manner and steer it onto a guide blade. The guide
blade fixed to the front suspension link diverts the air coming from the
brake air channel over the brake discs to the exterior. Together with a
front matched wheel spoiler, this has achieved effective cooling of the
brakes. The newly developed brake cover plates consist of steel at the
front axle and aluminium at the rear axle.
Electric parking brake with emergency braking function
As a new feature in the SL, the electrically operated parking brake
helps in the design of a generous interior. Its switch is located in the
dashboard, under the rotary light switch. Pressing this engages the
electric parking brake, and pulling releases it. It is also released
automatically as soon as the engine is running, the transmission is in
the D or R position, the driver has a fastened seat belt and the
accelerator is operated.
Under normal circumstances, irrespective of the duration of operating,
the electric parking brake only closes the responsible combined floating
brake calliper at the rear axle fully and for a sustained period when
the vehicle is at a standstill or at speeds below 4 km/h. Provision has
also been made for an emergency braking function: if the driver pressed
the electric parking brake at a speed higher than 4 km/h, the SL brakes
to a safe stop with the aid of the service brake. In this case, the
emergency braking function is taken care of by the hydraulic unit of the
ESP®, with the brake lights also lighting up.
The emergency braking is interrupted as soon as the control element is no longer kept depressed.
Torque Vectoring Brakes: ESP® helps with the steering
The new SL includes the Torque Vectoring Brakes system as part of its
standard specification. This ensures an additional safety margin at the
physical limits, makes the roadster even more agile and therefore
enhances its sportiness. The system achieves this with targeted,
one-sided braking intervention by the Electronic Stability Program ESP®
at the inside rear wheel when cornering. If ESP® detects a tendency to
understeer, the Torque Vectoring Brakes generate a defined turning or
yawing moment around the vehicle's vertical axis within fractions of a
second. Thanks to the different torque distribution that results, the SL
turns into the bend under precise control without any loss of handling
dynamics. The advantage of this solution over complex mechanical
components such as an active steering rear axle, additional multi-disc
clutches or an active differential is that the Torque Vectoring Brakes
can be implemented without an increase in vehicle weight and therefore
no disadvantages in terms of fuel consumption.
Wheels and tyres - a broad base for the SL
As part of its standard specification the SL350 is fitted with 17-inch
light-alloy wheels with 255/45 R17 tyres - options ranging up to 19-inch
wheels are available for selection on request. The SL500 is shod as
standard with 18-inch wheels with mixed-size tyres (8.5 J x 18 ET 35.5
with 255/40 R 18 tyres at the front, and 9.5 J x 18 ET 47.5 wheels with
285/35 R 18 tyres at the rear).
Safety: Top technology for the greatest possible safety
Mercedes-Benz drivers are safer than drivers of other brands when out on
the roads. This is the result of an investigation carried out by
Mercedes-Benz accident research on the basis of official, anonymised
random data checks by Germany's Federal Statistical Office. It
underlines the efficacy of the comprehensive Mercedes-Benz safety
philosophy. This involves the experts not contenting themselves with
achieving rating targets, but working intensively on attaining a level
of safety which far exceeds the standards stipulated by the world's
legislators. An important measure of their work is not the laboratory or
crash test facility, but actual accident incidents. The results of the
work carried out by the safety experts at Mercedes-Benz is known as Real
Life Safety, a concept which is based on research into thousands of
accidents. Using this irrefutable evidence, for their holistic safety
concept they have developed or initiated most of the assistance systems
which today effectively support drivers and have been adopted by many of
the company's competitors.
"The new Mercedes-Benz SL sets new standards for roadsters and can
confidently be referred to as the safest roadster in the world", remarks
Professor Dr Rodolfo Schöneburg, Director of Passive Safety at
Mercedes-Benz. "The rigid aluminium bodyshell offers superb
preconditions for a stable occupant cell, as well as for precisely
defined deformation zones. This provides optimum protection for the
occupants in the event of an accident. But we do not just think about
those inside the vehicle - we also consider the other road users, for
instance through effective pedestrian protection measures or assistance
systems which also protect other motorists."
During the development process for the new Mercedes-Benz SL-Class the
requirements of Euro NCAP and other rating institutes were taken into
account. The basis for this is a new light-alloy bodyshell which is
formed mainly by extruded sections and cast nodes made of aluminium. It
facilitates a light yet stable cell compound for a highly rigid occupant
cell. In conjunction with this the tail end and front are designed in
such a way that in the event of an accident they can absorb high forces
through deformation, thus considerably reducing the strain on the
occupants in a crash in accordance with the principle of the crumple
zone. The crash boxes behind the bumper trim and an exchangeable front
module ensure that the damage sustained during a front impact at up to
15 km/h can be limited.
Protection in the event of an overturn
The occupants in the new SL enjoy good protection in the case of a
potential overturn, too. A-pillars in a steel/aluminium material mix and
two roll-over bars can protect the passenger compartment. Normally the
two roll-over bars are completely recessed, so they do not interrupt the
look of the elegant, luxury roadster's flowing lines. They are located
in two cartridges fixed to the bodyshell in the area behind the seat
backrests. If the system of crash sensors detects a potential overturn,
the airbag control unit emits a signal and the deployment mechanism is
activated. Two preloaded pressure springs per cartridge see to it that
the roll-over protection shoots to the support position in fractions of a
second.
Headbag and crash-responsive head restraints
The restraint systems with two-stage driver and front passenger airbags
have been enhanced. A headbag provides generous lateral protection for
the head impact area. An additional thorax airbag in the seat backrest
can protect the upper body in the event of a side impact. The seat
belts, with inertia-reel tensioners and belt force limiters, serve to
highlight the high safety standards of Mercedes-Benz.
Another new feature finding its way into the standard equipment of the
SL comes in the form of the NECK-PRO crash-responsive head restraints,
developed by Mercedes-Benz. They can support the driver's and
passenger's head in the event of a rear impact and reduce the risk of
whiplash. Also fitted as standard is automatic child seat recognition.
The ISOFIX system is available as an optional extra.
Protection for pedestrians
The new Mercedes-Benz SL-Class Roadster uses the latest technology in
the area of pedestrian protection, too. A sensor system is able to
register an impact with a pedestrian and can ensure that the bonnet is
immediately raised by 85 mm in the rear section. This creates additional
space between the bonnet and the components in the engine compartment.
This in turn results in comparatively lower acceleration values for the
head of a pedestrian during the impact, thus reducing the overall risk
of injury.
The deformation properties of the bonnet have also been specifically
designed to meet the requirements concerning pedestrian protection. It
consists of aluminium with a homogenous reinforcement on the inside of
the bonnet and can therefore further reduce the loads in case of an
accident. The SL's "soft nose" also provides a large impact area, whilst
the foam density and geometry in the front bumper have been optimised
for reduced loads during leg impact with the pedestrian.
Only available from Mercedes-Benz - the anticipatory occupant protection system PRE-SAFE®
An additional safety highlight is the standard-specification
anticipatory occupant protection system PRE-SAFE®, a system developed by
Mercedes-Benz and unique throughout the world. If it detects an acute
risk of an accident, it reflexively activates precautionary protective
measures for the vehicle occupants, also including the reversible,
electromotive belt tensioning function which ensures that the occupants
are better secured so that the seat belts and airbags are able to
perform their protective function to the full during an impact.
Mercedes-Benz developed PRE-SAFE® on the basis of research into actual
accidents, and is the only manufacturer in the world to offer such a
system.
Following an accident - optimally prepared
Mercedes-Benz's holistic safety concept involves considering the phase
after an accident. This is why the new SL has numerous post-crash
measures incorporated on board which facilitate rapid assistance should
the worst come to the worst: depending on the type of accident and the
impact severity, the doors can be automatically unlocked, the interior
lighting activated and the side windows opened by 50 millimetres to
provide better ventilation in the interior. In addition to this, the
steering wheel can be slid upwards. The concept is completed by the
Guidelines for Rescue Services and the rescue cards which can be
downloaded from the internet free of charge and which can serve as a
valuable support for fire brigades.
ATTENTION ASSIST and ADAPTIVE BRAKE as standard
The new SL also features a unique combination of driver assistance
systems which help to avoid accidents. These include the drowsiness
detection system ATTENTION ASSIST, for example. Thanks to this system,
the roadster develops a precise feeling for the level of attentiveness
of the driver and can provide an early warning of overtiredness.
Also making up part of the standard equipment specification is the
ADAPTIVE BRAKE. It comprises ABS, the acceleration skid control system
ASR and also active yaw control (GMR). In addition, it features the
following functions:
it supports the driver when moving off uphill, by preventing the vehicle from unintentionally rolling back;
it also keeps the vehicle stationary without having to keep the
brakes applied continuously - for example when waiting at traffic
lights;
as soon as the driver abruptly steps off the accelerator, it brings
the brake pads into light contact with the brake discs as a
precautionary measure, so that the necessary braking pressure can be
attained quicker in the possible event of emergency braking;
in wet conditions it applies light brake contact, without the driver even noticing, to dry the brake discs.
The ADAPTIVE BRAKE works in conjunction with the equally adaptive brake
lights. In emergency braking situations, it warns vehicles behind with
rapidly flashing brake lights.
PRE-SAFE® Brake: autonomous partial and emergency braking in response to a serious risk of a rear-end collision
Available as optional extras are the DISTRONIC PLUS proximity control as
well as the PRE-SAFE® Brake, already tried and tested in other
Mercedes-Benz models. The two systems together and can initiate
emergency braking automatically on detecting an acute risk of an
accident.
In normal driving conditions, the radar-based DISTRONIC PLUS proximity
control adjusts the distance to the vehicle in front automatically. If
necessary, it can apply the brakes, even bringing the SL Roadster to a
stop, and accelerate it again. This takes some of the strain off the
driver, particularly in bumper-to-bumper driving conditions. If the
distance starts to narrow too quickly, the system gives the driver
visual and acoustic warnings, thereby prompting the driver to take
action, at which point they are also supported by Brake Assist PLUS (BAS
PLUS).
If the systems detect the acute danger of a rear-end collision and the
driver fails to respond to visual and acoustic warnings, the electronics
activate the PRE-SAFE® Brake in preparation for autonomous braking.
This happens in two stages:
Around 1.6 seconds before the calculated impact point, the car initiates
autonomous partial braking with around 40 percent (approx. four m/s²)
of the maximum braking power, gives the driver an additional, haptic
warning of the impending impact and as a precaution activates the
reversible PRE-SAFE® occupant protection systems.
If the driver still fails to react, the PRE-SAFE® Brake activates the
maximum braking power around 0.6 seconds before the now unavoidable
collision - this emergency braking can greatly reduce the severity of
the impact. The system therefore acts like an "electronic crumple zone",
offering the car occupants even greater protection.
The PRE-SAFE® Brake is active at speeds of between 30 and 200 km/h when
moving vehicles are detected in front of the car. The system also reacts
if the car approaches a stationary queue of traffic, providing the
car's speed is below 70 km/h.
The functionality of DISTRONIC PLUS has been enhanced even further. It
now reacts earlier to vehicles which cut in, and the car accelerates
quicker when changing lanes itself and where the overtaking lane is
clear. Thanks to the incorporation of information from digital maps
(navigation mode), automatic control has also been further refined.
Intelligent Light System - good vision at all times
The Intelligent Light System also comes as part of the standard
specification. It offers variably controllable headlamps with five
different light functions which are adapted to suit driving and weather
situations commonly encountered. They switch themselves on depending on
the prevailing driving situation, offering the motorist a considerably
greater field of vision:
The country mode distributes the light from the low-beam headlamps
in such a way that the left edge of the carriageway is illuminated more
brightly and across a larger area.
The motorway mode switches on from a speed of 90 kilometres per hour and enlarges the field of vision by as much 60 percent.
The cornering light function is automatically activated when the
main headlamps are on and if the driver operates the indicator or turns
the steering wheel at a speed below 40 km/h. The low-beam headlamps and
fog lamps then illuminate the side area ahead of the vehicle to a range
of around 30 metres at an angle of up to 65 degrees.
The active light function improves illumination of the road on bends by up to 90 percent.
The enhanced fog light function works by pivoting the left-hand
bi-xenon headlamp outwards by several degrees and lowering its beam.
This provides brighter illumination of the inner half of the road.
Adaptive Highbeam Assist is also on board as part of the standard
specification: when vehicles are detected ahead of or approaching the
vehicle, this system automatically dips the beams and adjusts the range
of the headlamps according to the distance.
The assistance systems spring into action
Those wanting to can choose to extend the potpourri of assistance
systems in the new SL even further. They provide extra doses of both
safety and comfort. As an option Mercedes-Benz can equip the roadster
with the following helpful features:
Speed Limit Assist: it is able to detect speed limit signs using a
camera on the inside of the windscreen and indicate the respective
detected speed limit on a display in the instrument cluster and in
COMAND. (Standard-fit in conjunction with COMAND online).
Active Blind Spot Assist: it warns the driver when changing lanes if
a risk of collision is detected due to another vehicle in the
neighbouring lane being in the blind spot of the exterior mirror. If the
driver ignores the warning and nevertheless initiates the lane-changing
manoeuvre, the Active Blind Spot Assist intervenes. A brake actuation
counteracts the collision course. (Part of the driver assistance package
with DISTRONIC PLUS including the PRE-SAFE® Brake and Active Lane
Keeping Assist).
Active Lane Keeping Assist: this system kicks into action if the
Mercedes-Benz vehicle inadvertently drifts over a solid line to the
right or left of a lane. In such a case, a warning sign in the
instrument cluster and vibrations in the steering wheel warn the driver.
If the driver does not heed the warning in the case of a solid line,
Active Lane Keeping Assist can use the ESP® to brake the opposite wheels
and thereby prevent the vehicle from crossing the solid line. (Also
part of the driver assistance package - please see above).
Hands off the steering wheel when parking
Active Parking Assist will answer the prayers of many drivers in the
chronically congested traffic areas of Europe: the SL can not only
detect parking spaces, but also help with the parking itself. This is
made possible thanks to a combination of the new electromechanical
Direct-Steer system (please see the chapter on the chassis and
suspension) and a series of ultrasonic sensors. This convenience system
features the following functions:
Measurement of potential parking spaces lengthwise to the direction
of travel - even in slightly curved bends - up to a drive-by speed of 30
km/h. The parking spaces must be at least one metre longer than the
vehicle.
Calculation of a suitable parking manoeuvre in order to park the vehicle parallel to the kerb.
Automatic steering in order to perform this parking manoeuvre.
Automatic steering in order to exit the parking space. This is only
possible if the parking space was entered using Active Parking Assist.
Two ultrasonic sensors take care of the search for suitable parking
spaces lengthwise in the direction of travel. They are integrated in the
front bumper, on the left and right. If the speed falls below 30 km/h, a
"P" symbol in the instrument cluster signals to the driver that the
active search for a parking place has been started automatically. If the
system has found a potential parking space, an arrow indicates this
alongside the "P" symbol. As standard, the arrow shows parking spaces on
the passenger side. If the indicator on the driver's side has been
activated, it shows potential parking spaces on the driver's side.
It is up to the driver to assess whether the free area designated by the
system is indeed actually a parking space. Even during the parking
procedure the responsibility remains with the driver. They activate the
accelerator and brake pedals during parking. The Active Parking Assist
takes care of the steering and for orientation it uses the two front
ultrasonic sensors as well as four further sensors in the rear bumper.
During parking, the roadster must not move faster than 10 km/h. The
automatic parking manoeuvre is configured for a maximum of five turns
(backwards-forwards-backwards-forwards-backwards). Once the vehicle is
standing correctly in the automatically selected parking space, the
system aligns the wheels.
The Active Parking Assist switches itself off as soon as the driver
intervenes in the automatic turning of the steering wheel, if the system
is turned off via the PTS button (Parktronic sensor), both if the
driver's seat belt buckle or the driver's door is open, or if there is a
system error. Nevertheless the familiar PARKTRONIC function remains
available without any restrictions.
Infotainment: The fully integral sound of tomorrow
As a rule, those gifted with a sensitive sense of hearing cannot expect
much listening enjoyment in a roadster. Even good car radios and CD
players are disappointing under these arduous acoustic conditions.
Instead, in open-top cars, the music flies away with the wind; it frays
and breaks up in all directions without its acoustic base - passengers
generally have to be satisfied with a woolly "sound carpet", or close
the roof. Open-air pleasure and musical enjoyment could hardly be
expected in a roadster. A great part of the blame for this lies with the
location of the bass loudspeakers in the doors or under a seat.
Mercedes-Benz now presents a solution to this conflict: the unique
Frontbass system, which at last creates the conditions for a concert
hall ambience in a roadster too. In the new SL, the Frontbass system is
celebrating its world premiere.
Crisp bass sound from the footwell
The principle sounds simple: Instead of being placed in the doors in the
usual way, in the new SL generation the bass loudspeakers are installed
in the footwell in front of the driver and passenger. This is not
possible with traditional vehicle shell structures, but the two front
longitudinal members in the front aluminium skeleton of the new
Mercedes-Benz SL-Class provide the resonance space needed for this
arrangement. The loudspeakers are fitted directly in two openings in the
firewall on either side of the footwell. Cavities in the longitudinal
members behind the speakers act as resonating chambers. The outstanding
inherent rigidity of these structural components results in
ultra-precise low notes with extremely little distortion, right up to
very high signal levels. In order words, the new SL features clear,
crisp bass sounds with a high dynamic range as part of its standard
equipment.
The position of these two independent closed woofers in the footwell
permits the creation of ideal acoustic conditions, because the firewall,
the vehicle floor and the underside of the dashboard form a sort of
funnel that focuses and concentrates the sound - a better sound
performance is the result. The acoustic effectiveness improves
significantly. The formula 'low energy plus lots of sound volume' saves
energy on top of it all. This way, the Frontbass system also contributes
towards a CO2 reduction.
Precise, brilliant sound
With the new Frontbass system, Mercedes-Benz is not only revolutionising
in-car bass sound reproduction - and in particular aboard an open-top
roadster - it is also creating the conditions for exceptional listening
enjoyment. Since the bass loudspeakers now do not need to be installed
in the doors, the disruptive acoustic vibrations typical of this
configuration no longer occur. In addition to this, the sound experts
have placed the mid-range and high-tone loudspeakers in the doors, the
dashboard and in the vehicle rear optimally close to the beltline and
thus almost at the same height as the SL occupants' ears. This way they
produce a precise, brilliant sound quality. The experts speak of an
exact stage reproduction with precise instrument representation and an
equally precise spatial graduation.
Even the standard entry-level Frontbass system creates a pronounced
encircling sound feel and an emotive sound experience, independently of
whether the vehicle roof is open or closed. As Norbert Niemczyk,
responsible for the new Frontbass system at Mercedes-Benz, explains:
"Our objective was not mere sound volume - although in this respect,
too, the system performs amazingly - but a clear sound instead, one that
never becomes "mushy". We have achieved this. All those who experienced
the sound with the Frontbass system for the first time got out of the
car with a big smile on their face - in-house we call that the Frontbass
smile."
Friendly to the surroundings: focused sound
Acoustic enjoyment of the highest level is part of the programme in the
new Mercedes SL both with a closed and with an open top. As the
Frontbass system focuses the sound, the powerful sound is concentrated
on the vehicle occupants - the surroundings are significantly less
disturbed than is the case with conventional sound systems. Apart from
this, the amplifier automatically controls the loudspeakers in a
different manner depending on whether the passenger compartment is
closed or open, according to the acoustic conditions, in order to create
the best possible sound.
Frontbass is always on board
The Frontbass concept is the standard basis in every version of the new
Mercedes-Benz SL. In the entry-level variant it is coupled with an
amplifier that is integrated in the COMAND head unit with an output of
4x25 watts, two Frontbass loudspeakers with a diameter of 217 mm, two
two-way systems for high and mid-range tones in the doors and two more
mid-range speakers in the rear.
The optionally available Harman Kardon® Logic 7® surround sound system
in conjunction with the Frontbass concept offers a further enhancement
and a musical delicacy of concert hall quality. The heart of the matter
is a Class D amplifier with a total output of 600 W and a digital signal
processor (DSP) for ten audio channels. The two Frontbass loudspeakers
and six two-way systems provide an even more precise and better defined
sound reproduction quality.
Finally, the ultimate in high-calibre pleasure for the eyes and ears
comes courtesy of the high-end Bang&Olufsen BeoSound AMG sound
system, also available as an optional extra. The Class D ICE power
amplifier and the Class D DSP amplifier with a total output of 900 watts
actively control the twelve high-end loudspeakers via separate
channels, thus ensuring the hallmark B&O crystal-clear sound
reproduction. Via the B&O-specific True Image menu various sound
settings such as the true-to-life studio-like reproduction in reference
mode or a space-optimised reproduction in surround mode can be selected -
and the sound fields can be precisely adjusted to the seats being used.
In addition to this, the automatic volume regulation function Vehicle
Noise Compensation automatically adjusts in accordance with the speed
and the exterior and interior noises measured with a microphone,
facilitating exclusive audiophile high-end sound at all times,
irrespective of external influencing factors such as noises caused by
the engine or the airflow.
High-end music enjoyment with the DVD "Mercedes-Benz Signature Sound"
So that SL drivers can fully appreciate and enjoy the Surround Sound and
the unique Front Bass system, Mercedes-Benz has edited an exclusive,
limited music DVD with the title "Mercedes-Benz Signature Sound". The
name stands for the unique signature sound of the musical pieces. It
comprises 15 well-known pop/rock songs and 10 masterworks of classical
music, re-worked and fine-tuned to the exceptional acoustic conditions
of the roadster by Grammy-winning experts at one of the best sound
studios in the world. Its transparent, crystal-clear sound provides a
musical experience of the highest level. The DVD "Mercedes-Benz
Signature Sound" can be found in every new SL Roadster that has been
ordered with a Surround Sound system.
Bodyshell tuned to Frontbass
In order to realise the Frontbass concept, the sound specialists worked
in close cooperation with the bodyshell designers right from the very
first planning stage. A small welcome side effect is that since the
Frontbass concept made the loudspeakers in the doors superfluous, the
designers were able to use the space made free in the doors for
additional stowage compartments.
