Fuel
Important safety notesGWARNING
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
personal injury.
Never allow sparks, flames or smoking
materials near gasoline.
Turn off the engine before refueling.
Whenever you are around gasoline, avoid
inhaling fumes and any skin or clothing
contact.
Direct skin contact with fuels and the
inhalation of fuel vapors are damaging to your
health.
Tank capacity
Total capacity18.5 US gal (70.0 l)Of which reserveApprox. 2.4 US gal (9.0 l)
Gasoline
Fuel grade
! Do not use diesel to refuel vehicles with a
gasoline engine. Even small amounts of the
wrong fuel result in damage to the fuel
system and engine.
! 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.
! To ensure the longevity and full
performance of the engine, only premium-
grade unleaded gasoline may be used.
If there is no premium-grade unleaded
gasoline available and regular unleaded
gasoline must be used, please 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 if the vehicle is carrying a light load, e.g.
two passengers without luggage, do not
allow the engine to rev above 3000 rpm.
R if the vehicle is fully loaded or is being
operated in mountainous terrain, do not
depress the accelerator pedal further
than Ô of the pedal travel.
Only refuel with premium-grade unleaded
gasoline with a minimum octane number of
91.
Reformulated Gasoline (RFG) and/or
unleaded gasoline with additives can be used.
However, the concentration of additives in
the fuel must be less than 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 pressureService products and filling capacities325Technical dataZ
You will usually find information about the fuel
grade on the pump. If you cannot find the
label on the pump, ask the staff for
assistance.
i For further information, consult an
authorized Mercedes-Benz Center or visit
http://www.mbusa.com (USA only).
Information on refueling ( Y page 146).
Additives
! 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.
One of the main problems of poor fuel quality
is the forming of deposits that are created
during the gasoline combustion process.
Mercedes-Benz recommends that you use
branded fuels that have additives.
If you use fuels without these additives over
a longer period of time, carbon deposits may
build up. These deposits form at the inlet
valves and in the combustion chamber in
particular.
This could lead to engine problems, e.g.:
R longer engine warm-up phase
R uneven idle
R engine noise
R misfiring
R loss of power
Carbon deposits may form if the availability
of gasoline with relevant additives is
insufficient (in certain regions). In this case,
Mercedes-Benz recommends additives
approved for use in Mercedes-Benz vehicles;
see http://bevo.mercedes-benz.com.
For a list of approved products, consult an
authorized Mercedes-Benz Center. Comply
with 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.
Engine oil
Please bear the following in mind
! Never use engine oil or an oil filter of a
specification other than is necessary to
fulfill 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
interval display regarding the oil change.
Otherwise, you may damage the engine and
the exhaust gas aftertreatment.
The engine oils are matched to the
performance 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
Center. Or visit the website
http://bevo.mercedes-benz.com.
The table shows which engine oils have been
approved for your vehicle.
ModelEngine
modelMB
ApprovalSLK 250271229.5SLK 350276SLK 55 AMG 23152
i
MB approval is indicated on the oil
containers.
23 Only SAE 0W-40/SAE 5W-40 engine oils may be used.326Service products and filling capacitiesTechnical data
Filling capacities
The following values refer to an oil change
including the oil filter.
ModelCapacitySLK 2505.8 US qt (5.5 l)SLK 3506.9 US qt (6.5 l)SLK 55 AMG10.0 US qt (9.5 l) 24
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 (viscosity)
classification 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 regular oil changes using an
approved engine oil with the appropriate SAE
classification.
Brake fluidGWARNING
Over a period of time, the brake fluid 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 Maintenance
Booklet.
Only use brake fluid approved by Mercedes-
Benz. Information about approved brake fluid
can be obtained at any qualified specialist
workshop or on the Internet at
http://bevo.mercedes-benz.com.
Coolant
Important safety notes
GWARNING
Antifreeze is highly flammable. Fire, naked
flames and smoking are prohibited when
handling antifreeze.
If antifreeze comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any antifreeze on hot
engine parts.
! 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 Specifications for
Service Products 310.1, e.g. on the
Internet at
http://bevo.mercedes-benz.com. Or
contact a qualified specialist workshop.
24 Including external oil cooler.Service products and filling capacities327Technical dataZ
! 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.
The coolant is a mixture of water and
antifreeze/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
coolant under operating conditions is
approximately 266 ‡ (130 †).
The antifreeze/corrosion inhibitor
concentration 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.
If the vehicle has lost coolant, add equal
amounts of water and antifreeze/corrosion
inhibitor. Mercedes-Benz recommends an
antifreeze/corrosion inhibitor concentrate in
accordance with MB Specifications for
Service Products 310.1.
The coolant is checked with every
maintenance interval at a qualified specialist
workshop.
i When the vehicle is first delivered, it is
filled with a coolant mixture that ensures
adequate antifreeze and corrosion
protection.CapacityModelCapacitySLK 250Approx. 10.1 US qt (9.6 l)SLK 350Approx. 11.0 US qt(10.4 l)SLK 55 AMGApprox. 10.0 US qt (9.5 l)
iUse MB 325.0 or MB 326.0 corrosion
inhibitor/antifreeze.
Washer fluid
GWARNING
Washer solvent/antifreeze is highly
flammable. Do not spill washer solvent/
antifreeze on hot engine parts, because it may
ignite and burn. You could be seriously
burned.
! Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or
MB WinterFit. Unsuitable washer fluid
could damage the plastic lenses of the
headlamps.
! Do not add distilled or de-ionized water to
the washer fluid container. Otherwise, the
level sensor may be damaged.
! Only MB SummerFit and MB WinterFit
washer fluid should be mixed together. The
spray nozzles may otherwise become
blocked.
At temperatures above freezing:
XFill the washer fluid reservoir with a mixture
of water and windshield washer fluid, e.g.
MB SummerFit.XAdd 1 part MB SummerFit to 100 parts
water.328Service products and filling capacitiesTechnical data