a generator and stores the recovered energy
in the high-voltage battery
R
when the brakes are applied lightly, the vehi-
cle is slowed down further by the electric
motor. This increases the energy recovery
taking place (
Y
page 240). The electric motor
operates as a generator and stores the recov-
ered energy in the high-voltage battery
R
when the brakes are applied with greater
force, the service brakes are also used to slow
the vehicle down. The two systems work
together
Urban driving
Energy is recuperated during frequent deceler-
ation and stopping in city traffic.
The vehicle can be driven by the electric motor
alone up to a speed of approximately 81 mph
(130 km/h).
The vehicle is driven by the electric motor alone
only when all conditions for the automatic
engine switch-off are fulfilled.
Further information on the automatic engine
switch-off (
Y
page 252).
Driving on inter-urban roads
The following phases are possible when driving
on inter-urban roads:
R
rapid acceleration (boost mode)
R
constant energy consumption
R
energy recuperation
R
electric operation mode
A great deal of recovered energy may be avail-
able, depending on the route profile. This
reduces consumption and emissions.
Highway driving
During highway driving, fuel consumption and
emissions are favorably influenced in particular
by reduced power losses.
The internal combustion engine will be switched
off automatically, if:
R
the driver removes his or her foot from the
accelerator pedal in drive program E and a
speed of 81 mph (130 km/h) is not exceeded
R
the driver removes his or her foot from the
accelerator pedal in drive program E+ and a
speed of 112 mph (180 km/h) is not excee-
ded
Further information on the automatic engine
switch-off (
Y
page 252).
ECO start/stop function
General notes
The ECO start/stop function switches the inter-
nal combustion engine off automatically when
the vehicle stops moving and at high speeds
(
Y
page 253).
All vehicle systems remain active, e.g. the auto-
matic climate control.
The ECO start/stop function is only available in
drive programs E and E+. Electric-only operation
is only possible in drive programs E and E+.
Additional information for drive programs E and
E+ (
Y
page 250).
Automatic engine switch-off
The engine is switched off automatically, includ-
ing when:
R
the driver removes his or her foot from the
accelerator pedal in drive program E and a
speed of 81 mph (130 km/h) is not exceeded
(
Y
page 253)
R
the driver removes his or her foot from the
accelerator pedal in drive program E+ and a
speed of 112 mph (180 km/h) is not excee-
ded (
Y
page 253)
R
the engine has reached its operating temper-
ature
R
the driver’s seat belt is fastened and the
driver’s door is closed
R
the driver only slightly depresses the accel-
erator pedal in order to, for example, maintain
the current speed for a limited distance
R
the hood is closed and engaged properly
R
the high-voltage battery is charged suffi-
ciently
R
no malfunctions are present in the hybrid
drive system
The internal combustion engine will not be
switched off automatically, if:
R
the self-diagnosis function of the engine con-
trol unit is still active
R
there is a malfunction in the hybrid drive sys-
tem
R
the climate control of the vehicle requires it
R
the high-voltage battery is being charged
(
Y
page 246)
R
automatic emissions tests are running
252
PLUG
‑
IN HYBRID operation
Dr
iving
and
par
king
