fuel MERCEDES-BENZ R-Class 2012 W251 Workshop Manual

Two instruction labels on your vehicle show
the maximum possible load.(1)The Tire and Loading Information placard
on the B-pillar on the driver's side. The
Tire and Loading Information placard
shows the maximum permissible number
of occupants and the maximum
permissible vehicle load. It also contains
details of the tire sizes and
corresponding pressures for tires
mounted at the factory.(2)The vehicle identification plate is on the
B-pillar on the driver's side. The vehicle
identification plate informs you of the
gross vehicle weight rating. It is made up
of the vehicle weight, all vehicle
occupants, the fuel and the cargo. You
can also find information about the
maximum gross axle weight rating on the
front and rear axle.
The maximum gross axle weight rating is
the maximum weight that can be carried
by one axle (front or rear axle). Never
exceed the maximum load or the
maximum gross axle weight rating for the
front or rear axle.:B-pillar, driver's sideMaximum permissible gross vehicle
weight rating
i The specifications shown on the Tire and
Loading Information placard in the
illustration are examples. The maximum
permissible gross vehicle weight rating is
vehicle-specific and may differ from that in
the illustration. You can find the valid
maximum permissible gross vehicle weight
rating for your vehicle on the Tire and
Loading Information placard.XThe Tire and Loading Information placard
gives you details on maximum permissible
gross vehicle weight rating :: "The gross
weight of occupants and luggage must
never exceed XXX kilograms or XXX
pounds."
The gross weight of all vehicle occupants,
cargo, luggage and trailer load/noseweight (if
applicable) must not exceed the specified
value.
Number of seats
i The specifications shown on the Tire and
Loading Information placard in the
illustration are examples. The number of
seats is vehicle-specific and can differ from
the details shown. The number of seats in
your vehicle can be found on the Tire and
Loading Information placard.
334Loading the vehicleWheels and tires

the week of manufacture, starting with "01"
for the first calendar week. Positions three
and four represent the year of manufacture.
For example, a tire that is marked with
"3208", was manufactured in week 32 in
2008.
Tire characteristics
i Tire data is vehicle-specific and may
deviate from the data in the example.
This information describes the tire cord and
the number of layers in sidewall : and under
the tread ;.
Definition of terms for tires and
loading
Tire ply composition and material
used
Describes the number of plies or the number
of layers of rubber-coated fabric in the tire
tread and sidewall. These are made of steel,
nylon, polyester and other materials.
Bar
Metric unit for tire pressure. There are
14.5038 pounds per square inch (psi) to
1 bar; there are 100 kilopascals (kPa) to
1 bar.
DOT (Department of Transportation)
DOT marked tires fulfill the requirements of
the United States Department of
Transportation.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by 68 kilograms
(150 lbs).
Uniform Tire Quality Grading
Standards
A uniform standard to grade the quality of
tires with regards to tread quality, tire traction
and temperature characteristics. Ratings are
determined by tire manufacturers using U.S.
government testing procedures. The ratings
are molded into the sidewall of the tire.
Recommended tire pressure
The recommended tire pressure for your
vehicle under normal driving conditions. You
will find the recommendation on the Tire and
Loading Information placard on the B-pillar on
the driver's side of your vehicle. The
recommended tire pressure provides the best
balance between handling characteristics,
ride comfort and wear. Supplemental
information pertaining to special driving
situations can be found on the tire inflation
pressure label on the inside of the fuel filler
flap.
Increased vehicle weight due to
optional equipment
This is the combined weight of all standard
and optional equipment available for the
vehicle, regardless of whether it is actually
installed on the vehicle or not.
Definition of terms for tires and loading343Wheels and tiresZ

Rim
This is the part of the wheel on which the tire
is mounted.
GAWR (Gross Axle Weight Rating)
The GAWR is the maximum permissible axle
weight. The actual load on an axle must never
exceed the gross axle weight rating. The
gross axle weight rating can be found on the
vehicle identification plate on the B-pillar on
the driver's side.
Tire speed rating
The tire speed rating is part of the tire
identification. It specifies the speed range for
which the tire is approved.
GTW (Gross Trailer Weight)
The GTW is the weight of a trailer including
the weight of the load, luggage, accessories
etc. on the trailer.
GVW (Gross Vehicle Weight)
The gross vehicle weight comprises the
weight of the vehicle including fuel, tools, the
spare wheel, accessories installed,
occupants, luggage and the drawbar
noseweight if applicable. The gross vehicle
weight must not exceed the gross vehicle
weight rating GVWR as specified on the
vehicle identification plate on the B pillar on
the driver's side.
GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permissible gross
weight of a fully loaded vehicle (the weight of
the vehicle including all accessories,
occupants, fuel, luggage and the drawbar
noseweight if applicable). The gross vehicle
weight rating is specified on the vehicle
identification plate on the B-pillar on the
driver's side.
Maximum loaded vehicle weight
The maximum weight is the sum of the curb
weight of the vehicle, the weight of the
accessories, the total load limit and the
weight of the optional equipment installed at
the factory.
Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa is the
equivalent of 1 psi. Another unit for tire
pressure is bar. There are 100 kilopascals
(kPa) to 1 bar.
Load index
In addition to the load bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifies the load bearing
capacity more precisely.
Curb weight
The weight of a vehicle with standard
equipment including the maximum capacity
of fuel, oil and coolant. It also includes the air-
conditioning system and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage.
Maximum load rating
The maximum load rating in kilograms or
pounds is the maximum weight for which a
tire is approved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire.
344Definition of terms for tires and loadingWheels and tires

Storing wheels
Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the
tires from oil, grease, gasoline and diesel.
Cleaning the wheels
GWARNING
Do not use power washers with circular-jet
nozzles (dirt grinders) to clean your vehicle, in
particular the tires. You could otherwise
damage the tires and cause an accident.
Wheel and tire combinations
Please bear the following in mind
! For safety reasons, Mercedes-Benz
recommends that you only use Tires and
wheels which have been approved by
Mercedes-Benz specifically for your
vehicle.
These tires have been specially adapted for
use with the control systems, such as ABS
or ESP ®
, and are marked as follows:
R MO = Mercedes-Benz Original
R MOE = Mercedes-Benz Original Extended
(tires featuring run-flat characteristics)
R MO1 = Mercedes-Benz Original (only
certain AMG tires)
Mercedes-Benz Original Extended tires
may only be used on wheels that have been
specifically approved by Mercedes-Benz.
Only use tires, wheels or accessories
tested and approved by Mercedes-Benz.
Certain characteristics, e.g. handling,
vehicle noise emissions or fuel
consumption, may otherwise be adversely
affected. In addition, when driving with a
load, tire dimension variations could cause
the tires to come into contact with the
bodywork and axle components. This could
result in damage to the tires or the vehicle.
Mercedes-Benz accepts no liability for
damage resulting from the use of tires,
wheels or accessories other than those
tested and approved.
Further information about tires, wheels and
approved combinations can be obtained
from any authorized Mercedes-Benz
Center.
i The Tire and Load Information placard
with the recommended tire pressures is
attached to the B-pillar on the driver's side.
Further information about driving at high
speeds or driving with vehicle loads that are
lighter than the maximum vehicle load can
be found in the tire pressure table on the
inside of the fuel filler flap. Check tire
pressures regularly, and only when the tires
are cold. Comply with the maintenance
recommendations of the tire manufacturer
in the vehicle document wallet.
For further information on the recommended
tire inflation pressure and on tire pressures
for specific driving conditions, see
( Y page 325).
i Notes on the vehicle equipment – always
equip the vehicle:
R with tires of the same size on a given axle
(left/right)
R with the same type of tires at a given time
(summer tires, winter tires, MOExtended
tires)
i Vehicles equipped with MOExtended tires
are not equipped with a TIREFIT kit at the
factory. It is therefore recommended that
you additionally equip your vehicle with a
TIREFIT kit if you mount tires that do not
feature run-flat properties, e.g. winter tires.
A TIREFIT kit can be obtained from an
authorized Mercedes-Benz Center.
i On the following pages, you can find
information on approved wheel rims and
tire sizes for equipping your vehicle with
winter tires. Winter tires are not available
from the factory as standard equipment or
optional extras.Wheel and tire combinations347Wheels and tiresZ

In addition to being stamped on the vehicle
identification plate, the vehicle identification
number (VIN) is also stamped onto the vehicle
body.
It is located on the floor in front of the right-
hand seat in the second row of seats.XSlide right-hand seat : of the second row
to its rearmost position.XFold floor covering = upwards.
You will see vehicle identification number
(VIN) ;.
Engine number
:Emission control information plate,
including the certification of both federal
and Californian emissions standards;Engine number (stamped into the
crankcase)=VIN (on the lower edge of the windshield)Service products and capacities
Important safety notes
Service products include the following:
R fuels (e.g. gasoline, diesel)
R additives for exhaust gas aftertreatment
(DEF)
R lubricants (e.g. engine oil, transmission oil)
R coolant
R brake fluid
R windshield washer fluid
Vehicle components and their respective
lubricants must match. You should therefore
only use products that have been tested and
approved by Mercedes-Benz.
Information on tested and approved products
can be obtained at a Mercedes-Benz Center
or on the Internet at http://
www.mbusa.com (USA only).
GWARNING
Comply with all valid regulations with respect
to handling, storing and disposing of service
fluids. Otherwise, you could endanger
persons or the environment.
Keep service fluids out of the reach of
children.
For health reasons, you should prevent
service fluids from coming into direct contact
with your skin or clothing.
If a service fluid is swallowed, contact a
physician immediately.
354Service products and capacitiesTechnical data

CapacitiesVehicle modelCapacityFuel, coolant,
lubricants etc.Engine oil and
filterR 350 BlueTEC9.0 US qt (8.5 l)Approved engine
oilsR 3507.9 US qt (7.5 l)Cooling systemAll modelsApprox. 10.0 US qt (9.5 l)MB 326.0 corrosion
inhibitor/antifreeze
agentTank capacityAll models21.1 US gal (80.0 l)Gasoline engines:
premium-grade
unleaded gasoline
(at least 91 octane,
average value
between 96 RON/
86 MON)
Diesel engines:
ULTRA-LOW
SULFUR HIGHWAY
DIESEL FUEL (ULSD,
maximum sulfur
content 15 ppm)ReserveAll modelsApprox. 3.4 US gal (13.0 l)DEF tankR 350 BlueTEC7.5 US gal (28.2 l)DEF in accordance
with ISO 22241Air-
conditioning
systemAll models—Refrigerant R134a
and special PAG
lubricant (never
R 12)Windshield/
headlamp
cleaning
systemAll models7.4 US qt (7.0 l)MB windshield
washer
concentrate 45
( Y page 360)
Mixing ratio for
washer fluid
( Y page 360)45
Mixed with water or premixed washer fluid with antifreeze protection.Service products and capacities355Technical dataZ

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
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.
356Service products and capacitiesTechnical data

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
Rengine 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
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.
Service products and capacities357Technical dataZ

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 (viscosity)
classification suitable for the prevailing
outside temperatures. The following table
shows the correct SAE classification 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 regular oil changes using an
approved engine oil with the appropriate SAE
classification.
Refrigerant of the air-conditioning
system
The air-conditioning system is filled with
R134a refrigerant and a special PAG
lubricant.
! Never use refrigerant R 12 (CFC) or
mineral lubricants. Otherwise, you could
damage the air-conditioning system.
Brake fluid
GWARNING
The brake fluid constantly absorbs moisture
from the air; this lowers its boiling point.
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 (e.g. when
driving downhill). This would impair braking
efficiency.
You should have the brake fluid renewed at
regular intervals. The brake fluid change
intervals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz. Information about approved brake
fluids can be obtained from any authorized
Mercedes-Benz Center.
Coolant
Important safety notes
The coolant is a mixture of water and
antifreeze/corrosion inhibitor. It performs
the following tasks:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
The engine cooling system is filled at the
factory with coolant which contains an
antifreeze/corrosion inhibitor that ensures
protection down to approximately -35 ‡
(-37 † ).
! Only add coolant that has been premixed
with the desired antifreeze protection.
Otherwise, the engine could be damaged.
Further information on coolants and on
filling can be found in the Mercedes-Benz
Specifications for Service Products, MB
Approval 310.1, e.g. on the Internet at
http://bevo.mercedes-benz.com . You can
also consult an authorized Mercedes-Benz
Center.
! Always use a suitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the cooling system will not be
sufficiently protected from corrosion, and
the boiling point will be too low.
If the coolant has antifreeze protection down
to -35 ‡ (-37 † ), the boiling point of the
Service products and capacities359Technical dataZ