2012 MERCEDES-BENZ GL-Class fuel pump

to spray back out when removing the fuel
pump nozzle, which could cause personal
injury.GWARNING
Do not fill diesel tanks with gasoline. Do not
mix diesel fuel with gasoline. Otherwise the
fuel system and engine could be damaged. In
addition, the vehicle could catch fire.
! Do not use gasoline to refuel vehicles with
a diesel engine. Do not use diesel to refuel
vehicles with a gasoline engine. Even a
small quantity of the wrong fuel will
damage the fuel system and engine.
! Do not switch on the ignition if you
accidentally refuel with the wrong fuel.
Otherwise, the fuel will enter the fuel lines.
Notify a qualified specialist workshop and
have the fuel tank and fuel lines drained
completely.
Gasoline
Fuel grade
! You should only refuel with unleaded
premium-grade gasoline as this avoids
damaging the catalytic converter.
If engine running problems are apparent,
have the cause checked immediately and
repaired. Excess unburned fuel can
otherwise enter the catalytic converter,
leading to overheating and possibly
causing a fire.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
i Only refuel with premium-grade unleaded
gasoline with a specified minimum octane
number of 91 (average value of 96 RON/
86 MON).
Usually, you will find information about the
fuel grade on the pump. If you cannot find
the label on the gasoline pump, ask the gas
station staff.
You can find more information under “Fuel”
( Y page 372), or by contacting an
authorized Mercedes-Benz Service Center
or visiting http://www.mbusa.com (USA
only).
Diesel
Fuel grade
! Only refuel with ULTRA-LOW SULFUR
DIESEL FUEL (ULSD, 15 ppm SULFUR
MAXIMUM). Using other diesel fuels could
result in increased wear and damage to the
engine and/or exhaust system.
Never refuel with marine diesel or heating
oil.
Do not mix these fuels with diesel fuels and
do not use any special additives, as this
may result in damage.
! Use a filter when adding fuel from a fuel
can. Otherwise, the fuel lines and/or the
fuel injection system could be blocked by
particles from the fuel can.
i Usually, you will find information about
the fuel grade on the pump. If you cannot
find the label on the gasoline pump, ask the
gas station staff.
You can find more information under “Fuel”
( Y page 372), or by contacting an
authorized Mercedes-Benz Service Center
or visiting http://www.mbusa.com (USA
only).
Low outside temperatures
! Do not use gasoline to refuel vehicles with
a diesel engine. Never mix diesel with
gasoline or kerosene, as this may result in
damage to the engine or fuel system.
Diesel fuel with improved cold flow properties
is available during the winter months. Further
information on fuel properties can be
160RefuelingDriving and parking

obtained from oil companies, e.g. at gas
stations.
Refueling
Fuel filler flap
The fuel filler flap is unlocked or locked
automatically when you open or close the
vehicle with the SmartKey or using KEYLESS-
GO.
The position of the fuel filler cap is displayed
in the instrument cluster 8. The arrow
next to the filling pump indicates the side of
the vehicle.
:To open the fuel filler flap;To insert the fuel filler cap=Fuel type?Tire pressure table
Opening
XSwitch off the engine.XRemove the SmartKey from the ignition
lock.
KEYLESS-GO: open the driver’s door. This
switches the ignition to position 0, which
corresponds to having removed the
SmartKey. The driver’s door can be closed
again.XPress the fuel filler flap in the direction of
arrow :.
The fuel filler flap opens slightly.XOpen the fuel filler flap.XTurn the fuel filler cap counter-clockwise
and remove it.XInsert the fuel filler cap into the holder
bracket on the inside of filler flap ;.XCompletely insert the pump nozzle into the
filler neck and refuel.XOnly fill the tank until the pump nozzle
switches off.
! Overfilling the fuel tank could damage the
fuel system.
Closing
XReplace the fuel filler cap and turn it
clockwise. The fuel filler cap audibly
engages.XClose the fuel filler flap.
i If you drive with the fuel filler cap open,
the reserve fuel warning lamp flashes. In
addition, the ! (USA only) or ;
(Canada only) Check Engine warning lamp
may light up. A message appears in the
multifunction display ( Y page 247).
For further information on warning and
indicator lamps in the instrument cluster,
see ( Y page 264).
i Close the fuel filler flap before locking the
vehicle. A locking pin otherwise prevents
the fuel filler flap from closing after the
vehicle has been locked.
Fuel filler flap emergency release
GWARNING
Avoid contact with the vehicle walls as they
may contain sharp edges. Otherwise, you
could injure yourself while releasing the fuel
filler flap.
The emergency release is located in the cargo
compartment behind the side trim on the
right-hand side, when viewed in the direction
of travel.
Refueling161Driving and parkingZ

Vehicle modelCapacityFuel, coolant,
lubricants etc.Air-
conditioning
systemAll models—Refrigerant R134a
and special PAG
lubricant (never
R 12)Windshield/
headlamp
cleaning
systemAll models7.6 US qt (7.2 l)MB windshield
washer
concentrate 48
( Y page 377)
Mixing ratio for
washer fluid
( Y page 377)Fuel
Important safety notesGWARNING
Gasoline and diesel fuels are highly flammable
and poisonous. They burn violently and can
cause serious injury.
Never allow sparks, flames or smoking
materials near gasoline or diesel fuel!
Turn off the engine before refueling.
Whenever you are around gasoline or diesel
fuel, avoid inhaling fumes and any skin or
clothing contact. Extinguish all smoking
materials.
Direct skin contact with fuels and the
inhalation of fuel vapors are damaging your
health.
Premium-grade unleaded gasoline
! To ensure the longevity and full
performance of the engine, only premium-
grade unleaded gasoline must be used.
If no premium-grade unleaded gasoline is
available and regular unleaded gasoline
must be used, observe the following
precautions:
R only fill the fuel tank to half full with
regular unleaded gasoline and fill the rest
with premium-grade unleaded gasoline
as soon as possible.
R do not drive at the maximum speed.
R avoid sudden acceleration.
R when the vehicle is carrying a light load,
e.g. two passengers without luggage, do
not allow the engine to rev above
3000 rpm.
R when the vehicle is fully loaded or in
mountainous terrain, do not depress the
accelerator pedal further than ⅔ of the
pedal travel.
Fuel requirements
Gasoline engines
Use only premium-grade unleaded gasoline.
The octane number should be at least 91.
Details can be found on the gas pump. The
octane number is the average value of the
Research Octane Number (RON) and the
48 Mixed with water or premixed washer fluid with antifreeze protection.372Service products and capacitiesTechnical data

Motor Octane Number (MON): (RON +
MON) / 2, also known as knock resistance.
Reformulated Gasoline (RFG) and/or
unleaded gasoline with additives can be used
if the concentration of the additives in the fuel
does not exceed 10%, e.g.:
R Ethanol
R TAME
R ETBE
R IPA
R TBA
For MTBE, the concentration should not
exceed 15%.
The concentration of methanol in gasoline
including other additives must not exceed 3%.
Using mixtures of methanol and ethanol is not
permitted. Gasohol, a mixture of 10% ethanol
and 90% unleaded gasoline, can be used.
All of these mix fuels must fulfill the fuel
requirements, e.g.:
R knock resistance
R boiling point
R vapor pressure
Diesel engines – Important safety notes
! Only use commercially available ULTRA-
LOW SULFUR DIESEL FUEL (ULSD, 15 ppm
MAXIMUM SULFUR) that meets the
ASTM D975 standard. Failure to use
ULTRA-LOW SULFUR DIESEL FUEL (ULSD)
can severely damage the vehicle's exhaust
gas aftertreatment system.
! Do not fill the tank with gasoline. Do not
blend diesel fuel with gasoline or kerosene.
Otherwise, the fuel system and the engine
could be damaged.
To prevent malfunctions, diesel fuel with
improved flow characteristics is available in
the winter months. Check with your gas
station.
Information on the fuel grade can usually be
found on the gas pump. If the information
cannot be found on the gas pump, ask the gas
station personnel. For further information,consult an authorized Mercedes-Benz Center
or go to the Internet site
http://www.mbusa.com (USA only).
Diesel engines – Fuels containing
biodiesel (FAME [fatty acid methyl ester])
Mercedes-Benz USA approves the use of B5
(ULSD with a maximum of up to five percent
by volume biodiesel) for all diesel engines
with common rail direct injection (CDI) and
BlueTEC.
Pure biodiesel and diesel fuels that have a
higher percentage of biodiesel, e.g. B20, can
damage the fuel system and the engine and
are therefore not approved.
For further information, please ask the gas
station personnel. The label on the gas pump
must indicate clearly that the B5 biodiesel
blend fulfills the ULSD standard. 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.
Additives in gasoline
One of the major problems with poor quality
fuels is the creation of carbon deposits during
the combustion process. Mercedes-Benz
recommends that you use fuel brands
containing additives that prevent the build-up
of carbon deposits.
If you use fuels without these additives for an
extended period of time, there may be a build
up of carbon deposits, especially on the inlet
valves and in the combustion chamber.
This could lead to engine running problems,
e.g.:
R longer engine warm-up phase
R uneven idle
R engine noise
R misfiring
R loss of power
In areas where the availability of gasoline with
relevant additives is not adequate, carbon
deposits can form. In this case, Mercedes-
Benz recommends the use of additives that
Service products and capacities373Technical dataZ

have been approved for Mercedes-Benz
vehicles.
Consult an authorized Mercedes-Benz Center
or go to the Internet site
http://www.mbusa.com (USA only) for a list
of approved products. Observe the
instructions for use on the product label.
Do not mix other fuel additives with fuel. This
causes unnecessary costs and could damage
the engine.
! Do not refuel with low-grade fuel and do
not use fuel additives that are not tested
and approved for Mercedes-Benz vehicles.
Damage to or malfunctions of the fuel
system may otherwise occur.
DEF
Important safety notes
i For BlueTEC vehicles only.
DEF is a non-flammable, non-toxic, colorless,
odorless and water-soluble fluid.
! Only use DEF that complies with
ISO 22241. Do not add any special
additives to DEF and do not thin DEF with
water. This could destroy the BlueTEC
exhaust gas aftertreatment.
! Rinse surfaces that have come into
contact with DEF immediately with water or
remove DEF using a damp cloth and cold
water. If the DEF has already crystallized,
use a sponge and cold water to clean it. DEF
residues crystallize after time and
contaminate the affected surfaces.
High outside temperatures
If DEF heats up over 122 ‡ (50 † ) for longer
periods, e.g. as a result of direct sunlight on
the DEF reservoir, DEF can decompose.
Ammonia vapors develop as a result.
GWARNING
When opening the filler cap of the DEF tank
ammonia gas vapors may escape. Refill DEF
in a well ventilated area only. Ammonia gas
vapors have a pungent odor and are
particularly irritating for your skin, mucous
membranes, and eyes. Inhaling ammonia gas
vapors will cause burning eyes, nose, and
throat, as well as coughing and watering eyes.
Low outside temperatures
DEF freezes at a temperature of
approximately 12 ‡ (–11 † ). The vehicle is
equipped with a DEF preheating system when
it leaves the factory. Winter operation is
therefore also guaranteed 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
aftertreatment system.
Damage resulting from the use of additives
or water is not covered by the Mercedes-
Benz Limited Warranty.
Purity
Assuring the purity of DEF is particularly
important with respect to avoiding
malfunctions in the exhaust gas
aftertreatment 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.
! Impurities in DEF, e.g. due to other
service products, cleaning agents or dust,
lead to increased emission values, system
malfunctions, catalytic converter damage
or damage to the BlueTEC system.
374Service products and capacitiesTechnical data