Stuttgart/Hochgurgl -
For years now,
Mercedes-Benz has been successful as a 4x4 manufacturer
in the premium segment. Production has soared since the launch of the
M-Class in 1997. Today, Mercedes-Benz offers nearly 50 models with
4MATIC across ten model series.
One of the fundamental factors in its
success is the formidable performance of the 4MATIC drive concept on
snow-covered or icy roads, with its high traction reserves, excellent
directional stability, peerless safety and exceptional comfort levels.
The new
CLS is capitalising on these
benefits too. For the first time, the four-door coupé is available with
all-wheel drive in the guise of the CLS 350 CDI 4MATIC BlueEFFICIENCY
and CLS 500 4MATIC BlueEFFICIENCY. Besides the CLS, the 4MATIC Workshop
being staged in extreme winter conditions on the Timmelsjoch high alpine
road in Austria also features the current versions of the
S-Class,
CL-Class and
R-Class.
As with the 4MATIC system's set-up on a dry or
wet road, directional stability and, therefore, active safety are
paramount at all times when wintry conditions prevail, too. The
mechanical principle of the 4MATIC system featuring a 45:55 torque split
between the front and rear axles and the multi-disc limited- slip
centre differential with a basic locking torque of 50 Nm offer all the
right ingredients. This basic design enables high levels of traction, as
the dynamic shift in axle load toward the rear axle that occurs during
acceleration is harnessed to deliver more drive torque to the rear
wheels. However, the multi-disc differential lock is also able to shift
the drive torque between the front and rear axles, varying the split as
the road conditions dictate.
Consequently, intervention by the ESP®,
4ETS or ASR electronic control systems can be delayed for as long as
possible and the bulk of the drive torque converted into tractive power,
even on slippery roads. All control system interventions go virtually
unnoticed, yet drivers still know straight away if they are driving on
the limit: in such instances, a yellow warning symbol flashes in the
instrument cluster as a highly visible prompt to adapt their driving
style to the road conditions.
The drive mechanism's permanently engaged design
offers key advantages over other systems that first need to diagnose a
lack of grip before activating the all-wheel drive. The 4MATIC system on
Mercedes-Benz models will have already made use of this valuable time
to start transmitting drive torque via the wheels to the road.
4MATIC: stable handling on snow and ice
When pulling away in wintry conditions, the
4MATIC models are designed to develop maximum traction. To this end,
certain road conditions are automatically detected and the interventions
of the 4ETS electronic traction control system adjusted so as to
achieve the greatest possible acceleration while minimising wheel slip,
ensuring optimum directional stability in the process. This strategy
also allows the vehicle to pull away under the most adverse conditions,
such as when one side of the vehicle is on an icy slope (µ-split) or
both wheels on either the front or rear axle have limited grip
(µ-jump).
On twisting roads covered with snow and ice,
vehicle stability is primarily controlled by the ASR acceleration skid
control system's regulation of engine torque. The ASR control thresholds
are adjusted according to the driving situation based on the vehicle's
longitudinal and lateral dynamic readings as continuously measured by
the ESP® sensor system. If vehicle stability is to be maintained, the
longitudinal force when cornering must be controlled by means of engine
torque regulation in such a way that there are sufficient reserves of
lateral force at all times. In order to comply with this physical
correlation, when cornering on road surfaces with a low friction
coefficient the control thresholds for engine torque regulation at the
wheels on the outside of the bend are reduced considerably so that the
tyres can develop sufficient lateral force.
4MATIC: cutting-edge technology breaks
new ground
The 4MATIC powertrain fitted in Mercedes-Benz
passenger cars is one of the best-performing permanent all-wheel drive
systems on the market. The basic design concept, with the engine
installed longitudinally and the integral transmission and transfer case
unit, produces a compact, lightweight arrangement that minimises
frictional losses, heralding a number of benefits compared to other
passenger car systems with a transverse power unit and selectable 4x4.
Depending on the particular model, fuel consumption, for instance, is a
mere 0.2 to 0.6 litres more per hundred kilometres than on an equivalent
vehicle with conventional drive, while vibration and acoustic comfort
meet the high standards expected of Mercedes-Benz vehicles.
CLS 4MATIC: stylish sportiness and
dynamism in the winter too.
Mercedes-Benz achieves the standard of driving
dynamics which the CLS is renowned for courtesy of the highly
sophisticated DIRECT CONTROL suspension with adaptive shock absorbers.
The weight-optimised DIRECT CONTROL system, featuring a three-link front
suspension and multi-link independent rear suspension, automatically
adapts to the changing driving situation by varying the damping forces,
resulting in a substantial improvement in ride comfort. The air
suspension system - optional for the CLS 350 CDI 4MATIC BlueEFFICIENCY
and standard on the CLS 500 4MATIC BlueEFFICIENCY - is combined with a
continuously variable, electronically controlled damping system that
processes a series of sensor signals and controls each wheel
individually. So, not only do Mercedes customers experience the best in
comfort, they reap the benefits of excellent handling safety and sporty
agility too.
A snug interior with a clear view:
THERMOTRONIC climate comfort. Carefully balanced control of the interior
climate is especially important in the winter. This is why Mercedes-Benz
offers the THERMOTRONIC luxury automatic climate control system. Apart
from regulating the climate separately for the driver, front passenger
and passengers in the rear, it allows individual pre-settings to be
programmed too. This system furthermore includes a pollutant sensor
which automatically switches to air recirculation mode if it detects any
sudden increase in the carbon monoxide or nitrogen oxide levels in the
outside air - when driving through a tunnel, for instance. Another
highlight of the THERMOTRONIC system is the residual heat function:
pressing the "Rest" button heats or ventilates the passenger compartment
for around 30 minutes when the engine is switched off.
THERMOTRONIC heats up the passenger compartment
extremely efficiently, even after a cold start on winter mornings. This
is thanks to a heating output of eleven kilowatts, equivalent to the
capacity of the central heating system in a modern family home. On the
diesel models, a heat exchanger with six integral PTC heating elements
(PTC = Positive Temperature Coefficient) is also activated when the
outside temperature falls below a certain level in order to boost the
effect of the main heat exchanger with an electrical output of around
1200 watts. The assistance from the PTC heater is necessary due to the
high thermal efficiency of today's CDI engines, which is precisely what
makes them so economical and means that they dissipate considerably less
heat to the coolant under partial load conditions than conventional
engines.
The Mercedes-Benz all-wheel drive line-up
currently encompasses 48 passenger car models across ten model series
and offers an impressively wide choice: besides the E-Class and the
C-Class, which both come in saloon and estate variants, the 4MATIC
portfolio is enriched by models from the S-Class, CL luxury coupé, CLS
four-door coupé and R-Class touring SUV ranges too. There is also the
compact GLK as well as the GL-Class and M-Class off-roaders. Still going
strong after 30 years in production, the G-Class truly comes into its
own off the beaten track and continues to rank as one of the best
cross-country vehicles in the world.
There is a reason why Mercedes engineers are so
skilled in the development of groundbreaking all-wheel drive concepts.
The history of all-wheel drive at
Mercedes-Benz dates all the way
back to 1903. Since then, the accepted maxim has been that all-wheel
drive is the best technology for making quicker and safer progress under
the most adverse conditions. Over the course of the years it has been
successfully employed in a variety of Mercedes-Benz models. Some models,
such as the G-Class and the Unimog, have attained legendary status all
over the world. But all-wheel drive has its benefits in everyday
operation on asphalt roads too, as demonstrated by the 4MATIC saloons
from Mercedes-Benz. The innovative drive concept received its saloon
premiere in the W 124 E-Class model series back in 1987. The 4ETS system
made its debut aboard the M-Class in 1997. Mercedes-Benz has therefore
amassed a wealth of experience with these electronic control systems -
more in fact than any other car manufacturer.
Source:
http://media.daimler.com/dcmedia/0-921-681308-1-1350914-1-0-0-0-0-1-11702-854934-0-1-0-0-0-0-0.html?TS=1293650341378