BONO
08-08-2003, 09:50 PM
The world's first standard-fitted seven-speed automatic transmission
for passenger cars will make future Mercedes models even more economical and further boost their acceleration. In addition, the new transmission variant will also considerably enhance shifting comfort
The new 7G-TRONIC seven-speed automatic transmission will be a
standard feature of the E 500,
S 430, S 500, CL 500 and SL 500 models from autumn 2003, replacing the
five-speed automatic version currently fitted.
The newly developed seven-speed automatic transmission reduces fuel
consumption in the NEDC
driving cycle by as much as 0.6 litres per 100 kilometres (depending
on the car), increases
acceleration from 0 to 100 km/h by up to 0.3 seconds and allows
significantly quicker
intermediate sprints from 60 to 120 km/h. At the same time, shifting
is even smoother, and
therefore more comfortable, than with the automatic transmission
presently used.
The Mercedes engineers have achieved these advances above all through
the use of seven gear
ratios. These allow the automatic transmission to retain the small
increases in engine speed
which are important in ensuring optimum gear ratios, whilst at the
same time offering a larger
ratio spread between the lowest and highest gear. This gives the
electronic control unit more
flexibility to adjust shifting in such as way as to keep fuel
consumption low and the
transmission's reactions fast. What's more, it also lowers the average
engine speed ? a clear
plus point in terms of both cutting fuel consumption and keeping the
lid on noise levels.
Fast gear-change using the principle of repeated downshift
When the driver switches down rapidly through the gears (kickdown),
the new transmission does
not always select the individual gears in strict order. Instead,
7G-TRONIC will miss out a
particular gear if necessary, switching from seventh gear straight
down to fifth, for example,
and from there directly to third. In this situation, only two gear
changes are actually
required ? instead of the normal four ? in order to accelerate quickly
using kickdown.
Shift quality, meanwhile, also hits new heights. The new transmission
glides through the gears
extremely smoothly and yet with impressive speed. Gear-change is
barely noticeable, especially
in the higher gears.
Torque converter lockup from first gear
As in its predecessor, one outstanding feature of the new seven-speed
automatic transmission
is a lockup clutch in the hydrodynamic torque converter. In many
situations, this system
largely eliminates slip between the pump and turbine rotor. It does
this by establishing a
virtually fixed connection wherever possible between the engine shaft
and transmission shaft,
creating an extremely effective barrier to output loss. In contrast to
conventional automatic
transmissions, in which torque converter lockup is only possible in
higher gears, the lockup
clutch in the new seven-speed automatic transmission from
Mercedes-Benz is active from the
first gear up.
Despite these significant technical advances, the 7G-TRONIC automatic
transmission is barely
any larger or heavier than the five-speed automatic transmission
currently fitted in Mercedes
passenger cars. Credit for this impressive achievement goes in
particular to the transmission
casing, which is constructed in lightweight magnesium ? also a world
premiere in volume
production.
Mercedes has produced eleven million automatic transmissions since
1959
The 7G-TRONIC transmission development represents the fifth generation
of automatic
transmissions made by the Mercedes-Benz brand, and in so doing
continues an impressive
tradition. Since 1959, the Stuttgart-based car maker has produced over
eleven million
automatic transmissions. Whilst the automatic transmission is part of
the standard equipment
in the S-Class, around 88 percent of all Mercedes E-Class customers
currently order their car
with automatic transmission, whilst the figure stands at some 65
percent for the C-Class
Saloons, Estates and Sports Coupés ? and this figure is on the rise.
The new seven-speed automatic transmission will be produced at the
Mercedes plant at
Stuttgart-Untertürkheim, the original location of the company's very
first production
facility. DaimlerChrysler has invested some 400 million euros at the
plant in the construction
of a new complex of buildings containing state-of-the-art production
equipment and installations for around 1100 employees.
for passenger cars will make future Mercedes models even more economical and further boost their acceleration. In addition, the new transmission variant will also considerably enhance shifting comfort
The new 7G-TRONIC seven-speed automatic transmission will be a
standard feature of the E 500,
S 430, S 500, CL 500 and SL 500 models from autumn 2003, replacing the
five-speed automatic version currently fitted.
The newly developed seven-speed automatic transmission reduces fuel
consumption in the NEDC
driving cycle by as much as 0.6 litres per 100 kilometres (depending
on the car), increases
acceleration from 0 to 100 km/h by up to 0.3 seconds and allows
significantly quicker
intermediate sprints from 60 to 120 km/h. At the same time, shifting
is even smoother, and
therefore more comfortable, than with the automatic transmission
presently used.
The Mercedes engineers have achieved these advances above all through
the use of seven gear
ratios. These allow the automatic transmission to retain the small
increases in engine speed
which are important in ensuring optimum gear ratios, whilst at the
same time offering a larger
ratio spread between the lowest and highest gear. This gives the
electronic control unit more
flexibility to adjust shifting in such as way as to keep fuel
consumption low and the
transmission's reactions fast. What's more, it also lowers the average
engine speed ? a clear
plus point in terms of both cutting fuel consumption and keeping the
lid on noise levels.
Fast gear-change using the principle of repeated downshift
When the driver switches down rapidly through the gears (kickdown),
the new transmission does
not always select the individual gears in strict order. Instead,
7G-TRONIC will miss out a
particular gear if necessary, switching from seventh gear straight
down to fifth, for example,
and from there directly to third. In this situation, only two gear
changes are actually
required ? instead of the normal four ? in order to accelerate quickly
using kickdown.
Shift quality, meanwhile, also hits new heights. The new transmission
glides through the gears
extremely smoothly and yet with impressive speed. Gear-change is
barely noticeable, especially
in the higher gears.
Torque converter lockup from first gear
As in its predecessor, one outstanding feature of the new seven-speed
automatic transmission
is a lockup clutch in the hydrodynamic torque converter. In many
situations, this system
largely eliminates slip between the pump and turbine rotor. It does
this by establishing a
virtually fixed connection wherever possible between the engine shaft
and transmission shaft,
creating an extremely effective barrier to output loss. In contrast to
conventional automatic
transmissions, in which torque converter lockup is only possible in
higher gears, the lockup
clutch in the new seven-speed automatic transmission from
Mercedes-Benz is active from the
first gear up.
Despite these significant technical advances, the 7G-TRONIC automatic
transmission is barely
any larger or heavier than the five-speed automatic transmission
currently fitted in Mercedes
passenger cars. Credit for this impressive achievement goes in
particular to the transmission
casing, which is constructed in lightweight magnesium ? also a world
premiere in volume
production.
Mercedes has produced eleven million automatic transmissions since
1959
The 7G-TRONIC transmission development represents the fifth generation
of automatic
transmissions made by the Mercedes-Benz brand, and in so doing
continues an impressive
tradition. Since 1959, the Stuttgart-based car maker has produced over
eleven million
automatic transmissions. Whilst the automatic transmission is part of
the standard equipment
in the S-Class, around 88 percent of all Mercedes E-Class customers
currently order their car
with automatic transmission, whilst the figure stands at some 65
percent for the C-Class
Saloons, Estates and Sports Coupés ? and this figure is on the rise.
The new seven-speed automatic transmission will be produced at the
Mercedes plant at
Stuttgart-Untertürkheim, the original location of the company's very
first production
facility. DaimlerChrysler has invested some 400 million euros at the
plant in the construction
of a new complex of buildings containing state-of-the-art production
equipment and installations for around 1100 employees.