
GWARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect,for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving.
GWARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
! Do not warm up the engine with the vehi-
cle stationary. Drive off immediately. Avoid high engine speeds and driving at full throt-
tle until the engine has reached its operat-
ing temperature.
Only shift the automatic transmission to
the desired drive position when the vehicle is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. You could otherwise damage the
drive train.
Key positions
SmartKey
gTo remove the SmartKey
(shift the transmission to position P)
1Power supply for some consumers, such
as the windshield wipers
2Ignition (power supply for all consumers)
and drive position
3To start the engine
The steering is locked when you remove the
SmartKey from the ignition lock.
iThe SmartKey can be turned in the igni-
tion lock even if it is not the correct Smart-
Key for the vehicle. The ignition is not
switched on. The engine cannot be started.
KEYLESS-GO
General notes
R Do not keep the KEYLESS-GO key:
- with electronic devices, e.g. a mobile
phone or another SmartKey
- with metallic objects, e.g. coins or metal
foil
- inside metallic objects, e.g. a metal case
This can impair the functionality of the KEY- LESS-GO key.
Vehicles with KEYLESS-GO are equipped with
a SmartKey featuring an integrated KEYLESS- GO function and a detachable Start/Stop but-
ton.
Driving149
Driving and parking
Z

! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
X Make sure that the windshield wipers are
turned off.
XPull release lever : on the hood.
The hood is released.
X Reach into the gap, pull hood catch han-
dle ; up and lift the hood.
If you lift the hood by approximately 15 in
(40 cm), the hood is opened and held open automatically by the gas-filled strut.
Closing the hood
X Lower the hood and let it fall from a height
of approximately 8 in (20 cm).
X Check that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force.
Engine oil
General notes on the oil level
Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per
600 miles (1,000 km). The oil consumption
may be higher than this when the vehicle is
new or if you frequently drive at high engine
speeds.
Depending on the engine, the oil dipstick may be in a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly, wait about 30 minutes
before carrying out the measurement.
Checking the oil level using the oil dip-
stick
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and
touch only the components described in the
following.
Example: vehicles with a gasoline engine
Engine compartment301
Maintenance and care
Z

Example: vehicles with a diesel engine
XPark the vehicle on a level surface.
To check the oil level with the engine at
operating temperature, switch the engine
off and wait for approximately five minutes.
X Pull oil dipstick : out of the dipstick guide
tube.
X Wipe off oil dipstick :.
X Slowly slide oil dipstick : into the guide
tube to the stop, and take it out again.
If the level is between MIN mark = and
MAX mark ;, the oil level is correct.
X If the oil level has dropped to MIN mark =
or below, add 1.1 US qt (1.0 liter) engine oil.
Adding engine oil
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
If engine oil comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil is not spilled next to
the filler neck. Let the engine cool down and
thoroughly clean the engine oil off the com-
ponents before starting the engine.
HEnvironmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful to the environment.
! Only use engine oils and oil filters that
have been approved for vehicles with a ser-
vice system. You can obtain a list of the
engine oils and oil filters tested and
approved in accordance with the
Mercedes-Benz Specifications for Service
Products at any Mercedes-Benz Service
center.
Damage to the engine or exhaust system is caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R replacing engine oil and oil filters after
the interval for replacement specified by
the service system has been exceeded
R using engine oil additives.
! Do not add too much oil. If the oil level is
above the "max" mark on the dipstick, too
much oil has been added. This can lead to
damage to the engine or the catalytic con-
verter. Have excess oil siphoned off.
Example: engine oil cap
X Turn cap : counter-clockwise and remove
it.
X Add engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, add 1.1 US qt (1.0 l) of
engine oil.
302Engine compartment
Maintenance and care

XReplace cap : on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.
X Check the oil level again with the oil dip-
stick ( Y page 301).
Further information on engine oil
( Y page 377).
Checking and adding other service
products
Checking coolant level
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
The engine cooling system is pressurized, par-ticularly when the engine is warm. When
opening the cap, you could be scalded by hotcoolant spraying out. There is a risk of injury.
Let the engine cool down before opening the
cap. Wear eye and hand protection when
opening the cap. Open the cap slowly half a
turn to allow pressure to escape.
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled down.
X Turn the SmartKey to position 2 in the igni-
tion lock ( Y page 149).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice ( Y page 149).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).
XSlowly turn cap : half a turn counter-
clockwise and allow excess pressure to
escape.
X Turn cap : further counter-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough coolant in coolant expansion tank ;.
If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar = in the fuel
filler neck when warm, there is enough
coolant in expansion tank ;.
X If necessary, add coolant that has been tes-
ted and approved by Mercedes-Benz.
X Replace cap : and turn it clockwise as far
as it will go.
For further information on coolant, see
( Y page 378).
Adding washer fluid to the windshield
washer system/headlamp cleaning
system
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and
touch only the components described in the
following.
Engine compartment303
Maintenance and care
Z

Bio-diesel – FAME (fatty acid methyl ester)Mercedes-Benz USA approves the use of bio-diesel B5 for all BlueTEC diesel engines. The
concentration of bio-diesel in the ULSD may
not exceed 5% by volume.
Pure bio-diesel and diesel fuel with a higher
percentage of bio-diesel, such as B20, can
damage the engine and the fuel system. For
this reason, they are not approved.
For more information, consult the gas station
staff. The bio-diesel B5 label on the gasoline
pump must clearly state that the standard for
ULSD has been fulfilled. If the label is not
clear, do not refuel the vehicle.
Do not refuel your vehicle with fuels unless
they have been approved by Mercedes-Benz.
Information on refueling ( Y page 163).
Low outside temperatures
iDiesel fuel with improved cold flow prop-
erties is available during the winter months. Further information about fuel properties
can be obtained from oil companies, e.g. at gas stations.
DEF
Important safety notes
Comply with the important safety notes for
service products when handling DEF
( Y page 373).
DEF is a water-soluble fluid for the exhaust
gas aftertreatment of diesel engines. It is: R not poisonous
R colorless and odorless
R not flammable
When you open the DEF container, small
amounts of ammonia vapor may be released.
Ammonia vapors have a pungent odor and are particularly irritating to the skin, to mucous
membranes and to the eyes. You may expe-
rience a burning sensation in your eyes, nose and throat. Coughing and watering of the
eyes are possible. Do not inhale ammonia vapors. Fill the DEF
tank only in well-ventilated areas.
Low outside temperatures
DEF freezes at a temperature of approx-
imately 12 ‡ (-11 †). The vehicle is delivered
from the factory equipped with a DEF pre-
heating system. Winter operation can thus be guaranteed even at temperatures below 12 ‡
(-11 †).
Additives
! Only use DEF in accordance with ISO
22241. Do not use additives with DEF and
do not dilute DEF with water. This may
destroy the BlueTEC exhaust gas after-
treatment system.
Purity
! Impurities in DEF (e.g. due to other ser-
vice products, cleaning agents or dust) lead to:
R increased emission values
R damage to the catalytic converter
R engine damage
R malfunctions in the BlueTEC exhaust gas
aftertreatment system
Assuring the purity of DEF is particularly
important with respect to avoiding malfunc-
tions in the BlueTEC exhaust gas aftertreat-
ment system.
If DEF is pumped out of the DEF tank, e.g.
during repair work, it must not be returned to
the tank. The purity of the fluid can no longer
be guaranteed.
Filling capacities
ModelTotal capacity
GLK 250 BlueTEC
4MATIC7.3 US gal (27.5 l)
376Service products and filling capacities
Technical data

Engine oil
General notes
! Never use engine oil or an oil filter of a
specification other than is necessary to ful- fill the prescribed service intervals. Do not
change the engine oil or oil filter in order to
achieve longer replacement intervals than
those prescribed. You could otherwise
cause engine damage or damage to the
exhaust gas aftertreatment.
Follow the instructions in the service inter-
val display regarding the oil change. Other-
wise, you may damage the engine and the
exhaust gas aftertreatment.
When handling engine oil, observe the impor- tant safety notes on service products
( Y page 373).
The engine oils are matched to the perform-
ance of Mercedes-Benz engines and service
intervals. You should therefore only use
engine oils and oil filters that are approved for
vehicles with maintenance systems.
For a list of approved engine oils and oil filters, consult an authorized Mercedes-Benz Cen-
ter. Or visit the website
http://bevo.mercedes-benz.com.
The table shows which engine oils have been
approved for your vehicle.
ModelMB Approval
All models229.5
iMB approval is indicated on the oil con-
tainers.
Filling capacities
The following values refer to an oil change
including the oil filter.
ModelCapacity
All models6.9 US qt (6.5 l)
Additives
! Do not use any additives in the engine oil.
This could damage the engine.
Engine oil viscosity
Viscosity describes the flow characteristics
of a fluid. If an engine oil has a high viscosity, this means that it is thick; a low viscosity
means that it is thin.
Select an engine oil with an SAE classification (viscosity) suitable for the prevailing outside
temperatures. The table shows you which
SAE classifications are to be used. The low-
temperature characteristics of engine oils
can deteriorate significantly, e.g. as a result
of aging, soot and fuel deposits. It is therefore
strongly recommended that you carry out reg- ular oil changes using an approved engine oil
with the appropriate SAE classification.
Brake fluid
GWARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake fluid is too low, vapor pockets may form in the brake system when the brakes are applied
hard. This would impair braking efficiency.
There is a risk of an accident.
You should have the brake fluid renewed at
the specified intervals.
Service products and filling capacities377
Technical data
Z

When handling brake fluid, observe the
important safety notes on service products
(Y page 373).
The brake fluid change intervals can be found in the Maintenance Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB Approval 331.0.
Information about approved brake fluid can
be obtained at any qualified specialist work-
shop or on the Internet at
http://bevo.mercedes-benz.com.
iHave the brake fluid regularly replaced at
a qualified specialist workshop and the
replacement confirmed in the Maintenance
Booklet.
Coolant
Important safety notes
GWARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly clean the
antifreeze from components before starting
the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be
found in the Mercedes-Benz Specifications
for Service Products, MB BeVo 310.1, e.g.
on the Internet at
http://bevo.mercedes-benz.com. Or con-
tact a qualified specialist workshop.
! Always use a suitable coolant mixture,
even in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
iHave the coolant regularly replaced at a
qualified specialist workshop and the
replacement confirmed in the Maintenance Booklet.
Comply with the important safety precautions
for service products when handling coolant
( Y page 373).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R corrosion protection
R antifreeze protection
R raising the boiling point
If the coolant has antifreeze protection down to -35 ‡ (-37 †), the boiling point of the cool-
ant during operation is approximately 266 ‡
(130 †).
The antifreeze/corrosion inhibitor concentra- tion in the engine cooling system should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -35 ‡ (-37 †).
R not exceed 55% (antifreeze protection
down to -49 ‡ [-45 †]). Otherwise, heat
will not be dissipated as effectively.
Mercedes-Benz recommends an antifreeze/
corrosion inhibitor concentrate in accord-
ance with MB Specifications for Service Prod-
ucts 310.1.
iWhen the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures
adequate antifreeze and corrosion protec-
tion.
iThe coolant is checked with every main-
tenance interval at a qualified specialist
workshop.
378Service products and filling capacities
Technical data