The C4 with a 6-speed electronic gearbox system
Premiered on the C4 and mated to the HDi 110 DPFS
engine, the 6-speed electronic gearbox system is of an entirely new
This highly driveable engine boasts a range of advantages.
Electro-hydraulic gearbox control makes for smooth, fast gear
changing. At the same time, automated gear and clutch management
fuel consumption by between 3% and 5%, compared with a conventional
This new gearbox therefore provides a real alternative to manual and
automatic transmissions, not only in terms of driveability and comfort,
but also in terms of fuel economy and a particularly attractive
customer price. It joins the long list of innovative equipment
available on the C4, for safety, convenience and on-board comfort.
A vehicle of innovative design and features that has picked up an array
of prizes (including "World Car Design 2006" at the recent New
International Motor Show), the C4 is enjoying considerable market
success. More than 350,000 vehicles have been sold to date.
The C4 HDi 110 DPFS equipped with the new 6-speed
electronic gearbox system will be available from June 2006.
By means of automating gear changes and clutch control,
this new gearbox obtains a reduction of fuel consumption on the
order of 3 to 5% in comparison to a conventional manual gearbox. Fuel
savings are boosted by the presence of a 6th gear.
Due to its particularly fuel-efficient engine, the C4 HDi 110 DPFS with
the six-speed electronic gearbox system thus brings fuel consumption
down to 4.5 litres per 100 kilometres in a combined cycle, with CO2
emissions of 120 grams per kilometre.
The six-speed electronic gearbox system offers outstanding user comfort
and responsiveness to the driver’s commands. Its electro-hydraulic
control system ensures smooth and lightning-fast gear changes in a
wide range of transmission ratios, which makes driving with this
gearbox particularly pleasant.
The new gearbox permanently adapts to the driver’s behaviour and
reinforces his driving sensations in sports mode, which makes
gear changes even faster. It also offers him peace of mind and driving
comfort with the hill-hold control and easy acceleration
dosage when manoeuvring, particularly in reverse.
The six-speed electronic gearbox system offers a real alternative to
conventional automatic or manual transmissions – by the driving
pleasure it procures as much as by the fuel savings it generates and
its attractive price.
This new gearbox expands the offer of automated manual gearboxes
already available in the CitroŽn range. These are proposed in
combination with petrol and diesel engines in the C1, C2,
C3 and C3 Pluriel models. Since its
introduction in 2002, 130,000 of these subcompacts were sold with the automated manual gearbox
DRIVING PLEASURE IN MANUAL MODE AND IN AUTOMATED MODE
The electronic gearbox system gives the driver a choice
between two driving modes:
a manual mode
in which he retains full control over gear changes by using the shift
paddles behind the steering wheel or the sequential shift lever.
an automated mode in which the gear selection
is managed by the gearbox control unit.
any time, the driver can switch from one mode to the other, depending
on his preferences and his environment: main road, motorway, city,
Driving without constraints in manual mode
activating manual mode, the driver decides at which moment he or she
wants to change gears, while at the same time benefiting from the
absence of the clutch pedal.
The driver is permanently informed about the selected gear by the
information displayed on the instrument panel.
He or she can change gears with the help of two types of controls,
which are perfectly substitutable:
Shift paddles behind the steering wheel
right-hand paddle is used to change up, and the left-hand paddle to
change down. These paddles give access to the six forward speeds. For
maximum comfort and safety, the paddles are fixed, irrespective of the
position of the steering wheel.
The sequential lever
the shift gate, the manual mode is indicated by the letter M,
accompanied by the signs + for changing up and – for changing down.
safety reasons, only the shift lever can be used to put the car into
neutral (N) or reverse (R). The reverse gear is available when the
vehicle is moving at less than 3.5 kph.
The shift lever has stable
positions which indicate to the driver the operating mode chosen – at
the same time, this mode is always displayed on the instrument panel.
But even when the driver selects the manual mode, the automated manual
gearbox ensures a high level of driving comfort.
When the car slows down and stops (for example, when approaching a stop
sign or a traffic light), the gearbox changes down automatically until
it reaches 1st gear.
Automatic downshifting is a function of several criteria that are
managed by the control unit (insufficient engine speed, slope, sporty
driving style, etc.).
The gearbox control unit also facilitates downshifting by increasing
engine speed to make gear changes smoother and without jolts.
Stress-free driving in automated mode
In the automated mode, gear changes are managed
electronically in order to optimise driving comfort and fuel
This mode is activated by placing the lever in position A on the shift
gate. If the driver opts for this driving mode, the AUTO symbol is
displayed on the instrument panel, together with the gear engaged.
The gearbox control unit then selects the gear that is best suited
according to the auto-adapting shift patterns that are determined as a
function of the driver’s behaviour, the road type, engine rpm, vehicle
speed and grip conditions.
The system thus prevents situations in which engine speed is too high
or too low and proposes an economical shift pattern aimed at lowering
fuel consumption. Optimised gear change management produces fuel
savings on the order of 3 to 5% in comparison to a manual gearbox,
depending on driving cycles.
However, certain specific situations are immediately recognized and
taken into account by the gearbox. These include holding the engaged
gear in phases of sustained acceleration, downshifting when the car is
re-accelerating and holding the gear or downshifting to assist the
If the driver wants to take control of the gearbox while driving in
automated mode (for instance in an emergency situation or while
overtaking), he can do so immediately. He merely needs to touch one of
the paddles, and his shift request is taken into account by the
gearbox. If no additional manual command is issued by the driver during
a short period thereafter (approx. 20 seconds), the gearbox switches
back to automated mode.
ENHANCED DRIVING COMFORT, FUEL SAVINGS AND PEACE OF
Six speeds for more drivability and lower fuel
presence of six speeds in the electronic gearbox system enables it to
make optimal use of all the qualities of the engine and guarantees, in
both manual and automated mode, perfect responsiveness and smooth
operation of the gearbox as well as reduced fuel consumption and
optimal acoustic comfort.
The design of the automated gearbox facilitates the use of these six
speeds by the driver:
- In manual mode
it is sufficient to apply pressure to the paddles (or to flick the
shift lever) to shift to the desired gear. Changing gears no longer
requires successive moves of the shift lever or repeated clutch work.
- In automated mode, the gearbox makes optimal
use of the 6th gear to increase fuel savings.
Electro-hydraulic controls for smooth and speedy
to the use of new electro-hydraulic actuators, the six-speed electronic
gearbox system makes shifting gentle and smooth in both manual and
Smooth shifting (with virtually no jolts) is not
obtained at the expense of shifting speed. The six-speed electronic
gearbox system reconciles both and distinguishes itself by the speed
with which it manages gear changes.
The time for a gear change is:
- 0.8 seconds for changing a gear in manual mode,
- 1.2 seconds for changing a gear in automated mode.
addition, the six-speed electronic gearbox system offers precise and
easy dosage of acceleration during manoeuvres, particularly in reverse.
The accelerator responds quickly to all demands, smoothly and without
A sport mode for even more responsiveness
six-speed electronic gearbox system of the C4 also offers a sport mode.
This mode, which is available with both manual and automated operation,
constantly favours fast gear changes. The total time required for
shifting is thus brought down to 0.4 seconds in manual mode and 0.5
seconds in automated mode.
In automated mode, the sport mode is
obtained by implementing specific shift pattern: upshifts and
downshifts are triggered at higher engine speeds than in normal
The sport mode is activated by the S button on the shift gate. Once
selected, an S is displayed on the instrument panel.
Hill-hold control for more safety
improved safety, the C4 with six-speed electronic gearbox system is
equipped with a hill-hold control that facilitates starting off on a
On a slope, the control holds the vehicle for two seconds
after the driver has taken his foot off the brake. It thus makes it
possible to safely accelerate the car when starting off or manoeuvring
on a slope, and to re-start the car without any stress.
The ESP activates the hill-hold control and temporarily keeps the
brakes applied when the driver takes his or her foot off the brake to
This assistance is provided when starting on an uphill or downhill
slope, both in forward gear and in reverse, and the hill-hold control
is activated on slopes with a gradient of 3% and higher.