|
Price |
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-- |
Production |
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-- |
|
Engine |
3.5
liter V6 hybrid |
Weight |
-- |
|
Aspiration |
natural |
Torque |
284
lb-ft |
|
HP |
299
hp |
HP/Weight |
-- |
|
HP/Liter |
79.7
hp per liter |
1/4 mile |
-- |
|
0-62 mph |
-- |
Top Speed |
-- |
(from Daimler Press
Release) Mercedes-Benz is launching its first passenger
car model equipped with a hybrid drive system in summer 2009 - the S
400 BlueHYBRID. The combination of a modified V6 petrol engine and a
compact hybrid module makes the S 400 BlueHYBRID the world's most
economical luxury saloon with a spark-ignition engine. The NEDC
combined fuel consumption is a mere 7.9 litres per 100 kilometres.
This makes for the world's lowest CO2 emissions in this vehicle and
performance class - just 190 grams per kilometre. These exemplary
figures go hand in hand with assured performance. The 3.5-litre
petrol engine develops an output of 205 kW/279 hp, the electric
motor generates 15 kW/20 hp and a starting torque of 160 Nm. The
result is a combined output of 220 kW/299 hp and a combined maximum
torque of 385 newton metres. Moreover, the new S 400 BlueHYBRID is
the first series-production model to be equipped with a particularly
efficient lithium-ion battery specially developed for automotive
use. This is another major contribution by Mercedes-Benz to the
electrification of the car.
The new Mercedes-Benz S
400 BlueHYBRID is based on the S 350, and features an extensively
modified drive train. This encompasses a further development of the
3.5-litre V6 petrol engine, an additional magneto-electric motor,
the 7G-TRONIC seven-speed automatic transmission specially
configured for the hybrid module, the necessary operating and
control electronics, the transformer and a high-voltage lithium-ion
battery.
The compact hybrid
module is a disc-shaped electric motor that also acts as a starter
and generator. The system offers a double benefit, as it both helps
to save fuel and increases driving enjoyment. This is partly due to
the booster effect of the electric motor, as it powerfully backs up
the petrol engine with a maximum additional torque of 160 newton
metres during the high-consumption acceleration phase. The driver
benefits from the combined action of these two units in the form of
even more impressive torque characteristics and smooth, effortlessly
superior acceleration.
The hybrid module also
has a comfortable start/stop function, which switches the engine off
when the vehicle is at a standstill - for example at traffic lights.
When it's time to move off again, the electric motor almost
imperceptibly restarts the main power unit. This likewise makes a
contribution to fuel economy and environmental protection: because
the engine restarts first time, and practically instantly, emissions
are also minimised during the starting phase.
When the vehicle is
braked the electric motor acts as a generator, and is able to
recover braking energy by a process known as recuperation. Working
in finely tuned partnership, the electric motor supplements the
braking effect of the petrol engine and the wheel brakes to deliver
a smoothly progressive braking action. The recuperated energy is
stored in a compact yet highly efficient lithium-ion battery in the
engine compartment, and made available when required. This complex
system is managed by a high-performance control unit, which is
likewise located in the engine compartment.
A milestone on the road to
electrification
The centrepiece of the
modular, very compact and highly efficient hybrid drive system is
the new high-voltage lithium-ion battery, which was specially
developed for automotive use and is the first such unit worldwide to
be introduced in a series-production vehicle. In this way
Mercedes-Benz is making a trailblazing contribution to the
electrification of the car, with the S-Class once again playing the
role of the technological trendsetter.
Major advantages over
conventional nickel/metal hydride batteries include a higher energy
density and better electrical efficiency, together with more compact
dimensions and a lower weight. Thanks to space-saving installation
in the engine compartment, where it replaces the conventional
starter battery, the generous interior space and boot capacity of
the S 400 remain unchanged. The lithium-ion battery not only stores
energy for the electric motor, but is also connected to the 12-Volt
onboard network via the transformer to supply power to other
standard consumers such as the headlamps and comfort features. The
completely newly designed battery system consists of the cell block
with its lithium-ion cells and the cell monitoring system, the
battery management function, the high-strength housing, the cooling
gel, the cooling plate, the coolant feed and the high-voltage
connector.
Optimised thermal efficiency
lowers the engine's fuel consumption
The 3.5-litre V6 petrol
engine with variable valve control has been throughly re-engineered
and improved. In the process the development engineers made use of
the advantages offered by the Atkinson principle,where the expansion
phase is longer than the compression phase. The intake valve is kept
open slightly longer between the intake and compression phases,
which improves the engine's thermal efficiency while reducing the
specific fuel consumption and untreated emissions. A new cylinder
head, different pistons and a modified camshaft with different
camshaft control increase the output by 5 kW/7 hp to 205 kW/279 hp -
while reducing fuel consumption at the same time.
Especially on rural
journeys and on motorways, the S 400 BlueHYBRID achieves a further
efficiency improvement by moving the so-called operating point of
the petrol engine to produce a lower specific fuel consumption. The
extremely high start-off torque made possible by the boost effect of
the electric motor gives the driver a particularly exhilarating
feeling of powerful acceleration, while fuel consumption and
emissions are reduced.
The electric motor improves
efficiency
The compact, disc-shaped
electric motor, which is space-savingly installed in the torque
converter housing between the engine and the 7G-TRONIC seven-speed
automatic transmission, improves efficiency even further. This is a
3-phase AC external rotor magneto motor, which develops a peak
output of 15 kW/20 hp and a starting torque of 160 newton metres
with an operating voltage of 120 Volts.
This compact motor also
acts as a starter and generator, adopting the functions of both
these conventional ancillary units.
Sophisticated
interaction with the internal combustion engine makes numerous
additional functions possible that positively influence the
emissions and agility of the S 400 BlueHYBRID in equal measure.
Moreover, this disc-shaped motor effectively dampens torsional
vibrations in the drive train, thereby further reducing noise and
vibrations in the interior. The result is even more ride comfort for
both driver and passengers.
"Boost" effect for even more
driving pleasure
The overall system
offers extensive benefits: firstly by helping to save fuel, and
secondly by increasing driving pleasure with the help of the "boost"
effect, where the electric motor gives powerful assistance to the
petrol engine with its maximum torque of 160 newton metres right
from the beginning of the fuel-intensive acceleration phase. This
means that the hybrid drive system of the S 400 BlueHYBRID moves off
powerfully even from very low engine speeds, as the torque curve
impressively confirms. The additional torque of the hybrid module
also has a consistently positive effect during subsequent
acceleration phases. In all driving situations, the driver therefore
benefits from the interaction between the two units in the form of
powerful responsiveness and muscular torque - but without an
increased fuel consumption.
The S 400 BlueHYBRID
accelerates from zero to 100 km/h in 7.2 seconds, and reaches an
electronically governed top speed of 250 km/h. The S 400 BlueHYBRID
betters the already very favourable NEDC fuel consumption of the
conventionally powered S 350 by up to 2.2 litres per 100 kilometres.
CO2 emissions are reduced by 21 percent.
The start/stop function already
saves fuel when rolling to a stop
In addition the hybrid
module features an extremely comfortable and efficient start/stop
function, which already switches the engine off when the vehicle is
rolling to a stop at less than 15 km/h, for example before stopping
at traffic lights. When it's time to move off again, the electric
motor immediately and imperceptibly restarts the main engine as soon
as the driver releases the brake pedal or operates the accelerator.
This likewise contributes to fuel economy and environmental
conservation: as the engine restarts practically instantly,
emissions are also minimised during the starting phase. The
vibrations and jolts that are unavoidable when starting with a
conventional starter are also reduced to a minimum.
Steering and climatic
comfort remain unchanged, as both the steering servo pump and the
refrigerant compressor are electrically powered. Both systems
therefore continue to operate even when the vehicle is at a
standstill with the engine automatically switched off. The
intelligent control logic is able to detect whether the driver is
executing a turning or parking manoeuvre. In this case the automatic
start/stop function is temporarily deactivated, so that these
manoeuvres can be carried out in comfort.
Every braking action generates
electric power for the battery
When the vehicle is
braked, the electric motor acts as a generator and uses a process
known as recuperation to convert the kinetic energy into electrical
energy. This energy is stored in the compact yet highly efficient
lithium-ion battery, and made available when required.
In the process the
electric motor assists the engine braking effect of the internal
combustion engine in two smooth, seamless stages: In stage one, on
the overrun with no braking action, the electric motor acts as a
generator and begins to recuperate energy. Stage two commences as
soon as the driver lightly operates the brake pedal: the generator
output is then increased proportionally, and perceived as heavier
deceleration by the driver. Only when more brake pedal pressure is
applied are the wheel brakes activated in addition to recuperation.
In this way more electrical energy can be generated, while saving
wear and tear on the hydraulic braking system at the same time. To
make the best possible use of this double benefit, Mercedes
engineers also developed a new braking system with a new brake pedal
module for the S 400 BlueHYBRID.
Cleverly located control
electronics
Dedicated control
electronics are required to operate the 3-phase AC electric motor in
the 120-Volt high-voltage DC network. The current converter is
accommodated in the space formerly occupied by the starter. As the
control electronics heat up as a result of electric currents
measuring up to 150 amps, the system is equipped with its own,
additional low-temperature cooling circuit.
Mercedes-Benz engineers
have accommodated the transformer in the right front wheel arch,
where it facilitates the exchange of energy between the 120-Volt
high-voltage network and the 12-Volt onboard network - and also
allows the option of emergency starting with jump leads if the
standard battery should lose its charge. To ensure a consistently
high level of electrical efficiency, the transformer is likewise
cooled by a low-temperature circuit. The 12-Volt lead/acid battery
is installed in the boot, and not only supplies the standard
consumers but also the monitoring system for the high-voltage
components with energy. Thanks to its interaction with the
lithium-ion battery, it is considerably smaller in size and lighter
than usual.
Tried-and-tested automatic
transmission with a new configuration
Mercedes-Benz developers
also adapted the well-proven 7G-TRONIC automatic transmission to
suit the hybrid drive, with newly programmed software for the
transmission management system. A newly developed auxiliary oil pump
ensures reliable lubrication of the transmission even during phases
when the internal combustion engine is switched off.
This complex system is
managed by the modified high-performance engine control unit. This
incorporates extensive functions, and distinguishes between
operating conditions such as city traffic, rural journeys, motorway
driving or slow manoeuvring.
Hybrid status is shown in the
instrument cluster
The driver is also able
to monitor the status of the hybrid drive system visually. The
instrument cluster has a separate, centrally positioned, display
showing the energy flow during boost and recuperation phases, as
well as the battery charge status.
Seven-stage safety concept in
addition to the Mercedes-Benz standard
As is usual at
Mercedes-Benz, the development engineers gave safety aspects their
very special attention. Know-how incorporated into the
series-production car included long years of Daimler research
experience with fuel-cell technology. The challenge lay in not only
complying with all the worldwide and in-house legal crash test
requirements, but also in ensuring the greatest possible safety for
the electrical components. This safety system already applies in
production, includes workshop personnel during servicing and
maintenance, and also takes the emergency services into account when
passengers need to be recovered following an accident.
Accordingly the hybrid
technology of the S 400 BlueHYBRID is equipped with an extensive
7-stage safety concept.
1. In the first
stage all the wiring is colour-coded to eliminate confusion, and
marked with safety instructions. This prevents assembly errors
in production, and makes the regular quality checks easier to
carry out.
2. The second stage
comprises comprehensive contact protection for the entire system
by means of generous insulation and newly developed, dedicated
connectors.
3. As part of the
third stage, the world's first lithium-ion battery to be used in
a series-production model has been given a whole package of
carefully coordinated safety measures. This innovative battery
is accommodated in a high-strength steel housing, and also
secured in place. Bedding the battery cells in a special gel
effectively dampens any jolts and knocks. There is also a
blow-off vent with a rupture disc and a separate cooling
circuit. An internal electronic controller continuously monitors
the safety requirements and immediately signals any
malfunctions.
4. The fourth stage
of the safety concept includes separation of the battery
terminals, individual safety-wiring for all high-voltage
components and continuous monitoring by multiple interlock
switches. This means that all high-voltage components are
connected by an electric loop. In the event of a malfunction the
high-voltage system is automatically switched off.
5. Active
discharging of the high-voltage system as soon as the ignition
is switched to "Off", or in the event of a malfunction, is part
of the fifth stage.
6. During an
accident, the high-voltage system is completely switched off
within fractions of a second (stage six).
7. As the seventh
and last stage, the system is continuously monitored for short
circuits.
Thanks to its compact
dimensions and modular design, the additional weight of the overall
system is only 75 kilograms - including the comprehensive safety
systems. The superior driving experience for which a Mercedes is
known is therefore ensured by this trailblazing and very versatile
technology, which can be used for practically all Mercedes-Benz
model series. Moreover, the payload remains unchanged at 595
kilograms.
The intelligent
high-performance engine management system responds very sensitively
to different driving conditions, and optimally configures the drive
system for the relevant application, ensuring that both fuel
consumption and emissions are kept to the lowest possible level.
At standstill the
petrol engine is usually switched off, and therefore consumes no
fuel. The electric drive of the refrigerant compressor and
steering servo pump allows uninterrupted operation of the air
conditioning and power steering. Comfort is in no way
compromised, and is at the same high level as in all S-Class
models.
Moving off and
acceleratingaway gently remains a smooth and comfortable
procedure. A driver who kicks down the accelerator for a brisk
start benefits from the boost function of the electric motor,
which produces considerably more dynamic acceleration.
At constant
speedsthe intelligent electronics recognise situations such as
relaxed motorway stretches, and automatically adjust the load
point of the internal combustion engine to achieve a lower
specific fuel consumption, thereby helping to save fuel and
reduce emissions.
When rolling to a
stopthe recuperation function is activated as soon as the drive
is interrupted in any way (foot off the accelerator, engine
braking). Once the vehicle speed falls below 15 km/h, the petrol
engine is automatically switched off.
If the driver brakes
using the brake pedal, the electric motor initially begins to
convert the vehicle's kinetic energy into electrical energy. In
this case the electric motor acts as a generator, storing the
kinetic energy as electrical energy in the lithium-ion battery.
This process feels like a stronger engine braking effect to the
driver. The conventional disc brakes at the wheels are not yet
employed, saving wear and tear. The disc brakes are only
activated if the driver applies heavy pressure to the brake
pedal, braking the car together with the engine brake and
recuperation.
Once the driver
selects "R" (reverse) in the 7G-TRONIC automatic transmission
when manoeuvring, this automatically activates the Manoeuvring
mode and prevents the start/stop function from switching off the
engine at short, frequent intervals.
The advantages of
the hybrid drive system really come into their own in city
traffic, with frequent stops at red traffic lights. Already
switching off the petrol engine as the car frequently coasts to
a stop significantly lowers the fuel consumption and emissions,
while the long recuperation phases increase the battery charge.
The electric motor ensures particularly comfortable and rapid
restarting when the start/stop function is active.
On rural roadsthere
are frequent changes between boost, constant speed and
recuperation phases. Depending on the nature of the route, large
quantities of recuperation energy are available to reduce fuel
consumption and emissions. The more braking and acceleration
phases there are, the better: uphill and downhill gradients, as
well as winding, dynamic stretches, make for the largest
savings.
The hybrid effect is
inherently less important on motorways, however thanks to
specific modifications to the V6 petrol engine and the 7G-TRONIC
automatic transmission, the driver is also able to achieve
significant fuel savings and correspondingly lower emissions on
fast road stretches like these.
The S 400 BlueHYBRID is
produced at the Sindelfingenplant, together with the other S-Class
models. The petrol engine, 7G-TRONIC automatic transmission and
electric motor are first put together to form a hybrid module, then
delivered to the production line as a unit. The market launch in
western Europe is planned for June 2009; China is expected to follow
in August 2009 and the USAin September 2009.
Modular technologies for the
environmentally friendly future of the premium car
The new S 400 BlueHYBRID
exemplifies the strategy of Mercedes-Benz, whose declared aim is to
offer the brand's customers economical and environmentally
compatible premium cars - without compromising in terms of typical
brand attributes such as safety, comfort and a superior driving
experience.
Major areas of
development focus include modular drive technologies, which are used
on a stand-alone basis or in combination depending on the vehicle
class, operating profile and customer requirements - Mercedes-Benz
has already described how this applies to the product portfolio in
its "Road to the Future". In this context Mercedes-Benz also
provides an outlook on the future of the internal combustion engine,
with the innovative DIESOTTO engine in the F 700 research car.
Dedicated solutions for different
requirements
The requirements for the
cars of the future are complex and multi-facetted. This is because
the world population, and therefore the demand for mobility, are set
to increase drastically over the next few decades. At the same time
the world's natural resources are becoming increasingly scarce, and
therefore more and more expensive for both consumers and car
manufacturers. Depending on the world region, there are also
sometimes very different legal requirements with respect to the
environmental compatibility of vehicles. Examples include the
environmental zones already established in many European cities, or
the legally prescibed quotas for emission-free vehicles in
California.
These developments are
already having a noticeable effect on customer behaviour. In
addition to economic factors - above all increasing fuel prices -
the environmental compatibility of a car is becoming increasingly
important as a buying criterion. What is more, the day-to-day
driving requirements of customers are becoming more and more
individual and distinctive: drivers covering long rural distances
have different requirements from those who mainly or even
exclusively drive in densely populated urban areas.
In the view of
Mercedes-Benz, there is therefore no single technology that will
provide the ideal solution for sustainable mobility in the future.
Instead the company offers versatile, tailor-made solutions to meet
these very varied requirements. The individual technologies deliver
their benefits in terms of optimal fuel consumption and emissions in
the specific areas of application concerned. The approach taken by
Mercedes-Benz envisages vehicle concepts with modular drive
technologies, which ensure that customer benefits and environmental
compatibility are always jointly emphasised.
Roadmap for sustainable mobility
The corporate
development strategy is aimed at safeguarding the leading position
in the premium segment on a lasting basis. To this end three areas
of emphasis were defined in the roadmap for sustained mobility:
Vehicle optimisation
with the latest internal combustion engine technology - for
example by downsizing, high-pressure charging, direct injection
and the environmentally friendly diesel technology BlueTEC - as
well as specific vehicle improvements in the areas of
aerodynamics, lightweight construction and energy management (BlueEFFICIENCY),
for example.
Further efficiency
improvements by means of need-related hybridisation in various
development stages - from the start/stop function to the
two-mode hybrid operating under electric power alone.
Locally
emission-free driving with fuel-cell and battery-powered
vehicles.
The company is also
actively involved in the development of clean and alternative fuels
that do not compete with the production of foodstuffs - particularly
in SunDiesel, which is obtained from plant waste.
An intelligent mix of drive
systems as a solution for the mobility of the future
Mercedes-Benz has
already brought numerous answers to the challenges of tomorrow to
market. The most recent examples are the BlueEFFICIENCY models in
the A-Class, B-Class and C-Class, the natural-gas-powered B 170 NGT
and the powerful yet economical and clean BlueTEC SUVs, which were
first introduced into the US market this year. A mix of modular
drive systems, from the latest internal combustion engines with
BlueTEC or direct injection, with or without hybridisation, right up
to locally emission-free battery and fuel-cell-powered vehicles,
provides all the conditions that will enable Mercedes-Benz to offer
its customers need-related mobility to the brand's customary high
standard into the long-term future.
