2012 MERCEDES-BENZ SLK ROADSTER engine

If only regular unleaded petrol with an
octane rating of 91 RON/82.5 MON or
loweri s available, you must have the vehi-
cle adapted to this fuel at a qualified spe-
cialist workshop.
i E10 fuel contains up to 10% bioethanol.
Your vehicle is E10-compatible. You can
refuel your vehicle using E10 fuel.
SLK 350 BlueEFFICIENCY
! Only refuel using premium-grade sulphur-
free unleaded petrol with at least 95 RON/
85 MON that conforms to European stand-
ard EN 228 or an equivalent specification.
You could otherwise impair engine output
or damage the emission control system.
i In some countries, the available petrol
may not be sufficiently low in sulphur. This
fuel can temporarily produce unpleasant
odours, especially on short journeys. As
soon as sulphur-free fuel (sulphur content
<10p pm) is used for refuelling, the odours
are reduced.
Additives
! Do not refuel with low grade fuel and do
not use fuel additives that have not been
tested and approved for Mercedes-Benz
vehicles. Otherwise the fuel system could
malfunction or be damaged.
One of the major problems with low-grade
fuel is the creation of carbon deposits during
the process of burning fuel. Mercedes-Benz
recommends that you use fuel brands that
have additives.
If you use fuels without these additives for a
longer period of time, there may be a build-up
of carbon deposits. These will form 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 petrol with the required addi-
tives is not available, carbon deposits can
build up. In this case, Mercedes-Benz recom-
mends the use of additives that have been
approved for Mercedes-Benz vehicles; see
http://bevo.mercedes-benz.com.
Consult a Mercedes-Benz Service Centre to
view a list of approved products. Observe the
instructions for use in the product descrip-
tion.
Do not mix other fuel additives with fuel. This
causes unnecessary costs and could damage
the engine.
Diesel (EN 590) Fuel grade
G
WARNING
Do not use petrol to refuel vehicles with a die-
sel engine. Do not mix diesel with petrol. This
would result in damage to the fuel system and
engine, which could lead to a vehicle fire.
! When refuelling, only use diesel fuel that
conform stothe European standard EN 590
or is of equivalent quality. Fuel that does
not conform to EN 590 can lead to
increased wear as well as damage to the
engine and exhaust system.
! Do not use the following:
R marine diesel
R heating oil
R bio-diesel
R vegetable oil
R petrol
R paraffin
R kerosene
Do not mix these fuels with diesel fuels and
do not use any special additives. Other-
wise, this can lead to damage to the engine.
This excludes flow improver; see "Low out-
side temperatures". Service products and capacities
305Technical data Z

!
Vehicles with adiesel particle filter: in
countries outside the EU, only refuel with
low-sulphur Euro diesel with a sulphur con-
ten tunde r50p pm; otherwise the emission
control system could be damaged.
! Vehicles without adiesel particle fil-
ter: in countries where only diesel fuel with
a high sulphur conten tis available, you will
need to carry out your vehicle's oil change
at shorter intervals. More information
aboutt he interval for oil change can be
obtained from any qualified specialist
workshop.
Usually you will find information about the
fuel grade on the pump. If you cannot find the
label on the petrol pump, ask the filling sta-
tion staff.
Information on refuelling (Y page 142).
Low outside temperatures
In winter months, diesel fuel with an improved
cold flow quality is available. In Europe, the
EN 590 standard defines various climate-
dependent temperature categories. Malfunc-
tions can be avoided by refuelling with diesel
fuel that corresponds to the climatic specifi-
cations outlined in EN 590. At unusually low
outside temperatures, it is possible that the
flow characteristics of the diesel fuel could be
insufficient .Accordingly, diesel fuel from
warmer areas may not be suitable for opera-
tion in colder climati cconditions.
i Further information on country-specific
fuel properties can be obtained from oil
companies, e.g. at filling stations.
Flow improver
To improve the low-temperature resistance of
diesel fuel, a flow improver can be attached.
The effectiveness of a flow improver is not
guaranteed for every fuel.
Only use flow improvers tested and approved
by Mercedes-Benz. During use, please
observe the information on operation.
Correct dosage and sufficient mixing are deci-
sive in improving low-temperature resistance with the flow improver. Overdosage can
potentially even decrease low-temperature
resistance and must therefore be avoided.
Follow the manufacturer's guidelines on dos-
age.
Mix the additive into the diesel in good time,
before the flow characteristics of the diesel
become insufficient. Otherwise, malfunctions
can arise through heating the fuel system,
e.g. through parking in a heated garage.
More information about recommended flow
improvers can be obtained from any qualified
specialist workshop.
Notes on fuel consumption
H
Environmental note
CO 2(carbon dioxide) is the gas which scien-
tists believe to be principally responsible for
global warming (the greenhouse effect). Your
vehicle's CO 2emissions are directly related to
fuel consumption and therefore depend on:
R efficient use of the fuel by the engine
R driving style
R other non-technical factors, such as envi-
ronmental influences or road conditions
You can minimise your vehicle's CO 2emis-
sions by driving carefully and having it serv-
iced regularly.
The vehicle will use more fuel than usual in
the following situations:
R at very low outside temperatures
R in urban traffic
R on short journeys
R in mountainous terrain
i Only for certain countries: you can find
the current consumption and emission val-
ues of your vehicle in the COC documents
(EU CERTIFICATE OF CONFORMITY). These
documents are delivered with your vehicle.
The consumption figures were in each case
based on the currently applicable version: 306
Service products and capacitiesTechnical data

R
for vehicles up to and including the EURO
4s tandard, in accordance with EU Direc-
tive 80/1268/ECC
R for vehicles above the EURO 5standard,
in accordance with Regulatio n(EC) No.
715/2007
Deviations fro mthese values may occur
under normal operating conditions. Engine oil
Points to remember The quality of the engine oil is decisive for the
function and service life of an engine. After
extensive tests, Mercedes-Ben
zapproves
engine oils that correspond to the current
technical standard.
Therefore, only Mercedes-Benz approved
engine oils may be used in Mercedes-Benz
engines.
Further information on tested and approved
engine oils can be obtained from any
Mercedes-Benz Service Centre. Mercedes-
Ben zrecommends that you have the oil
change carried out at a qualified specialist
workshop. Mercedes-Benza pproval is indica-
ted on the oil container by the inscription "MB
Approval" and the corresponding designa-
tion, e.g. MB Approval 229.51.
You can call up an overview of approved
engine oils on the Internet at
http://bevo.mercedes-benz.com by enter-
ing the designation, e.g. 229.5.
The table shows which engine oils have been
approved for your vehicle. Petrol engines MB Approval
SLK 200
24
SLK 250 24 229.3, 229.5,
229.51
SLK 350
24 229.3, 229.5
SLK 55 AMG
25 229.5
Diesel engines MB Approval
Vehicles with
adiesel particle filter SLK 250 CDI
24 228.51,
229.31, 229.51
i
If the engine oils listed in the table are not
available, you may add the following engine
oils until the nex toil change:
R MB Approval 229.1 26
R ACEA A3 26
This may only be topped up once, and the
quantity must not be greater than 1.0 l.
Capacities The following values refer to an oil change
including the oil filter.
Model Replacement
amount SLK 200
27
SLK 250 27 5.5 l
SLK 350
27
SLK 250 CDI 27 6.5 l
SLK 55 AMG
9.5 l
28 24
BlueEFFICIENCY
25 Only SAE 0W-40/SAE 5W-40 engine oils may be used.
26 Only SAE 0W-40/SAE 5W-40 engine oils may be used for AMG vehicles.
27 BlueEFFICIENCY
28 Including external oil cooler. Service products and capacities
307Technical data Z

Additives
!
Do no tuse any additives with 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
rating, it flows slowly; the lower the viscosity,
the faster it flows.
Engine oil selection is based on the respective
outside temperatures and in accordance with
the SAE classification (viscosity). The table
shows you which SAE classifications are to be
used. The low-temperature properties of
engine oils can be significantly impaired dur-
ing operation due to, for example, ageing or
soot and fuel accretion. It is therefore
strongly recommended to observe regularo
il
changes using an approved engine oil with the
appropriate SA Eclassification. Brake fluid
G
WARNING
Over a period of time, the brake fluid absorbs
moisture fro mthe air; This lowers its boiling
point.
If the boiling point of the brake fluid is too low,
vapour pockets may form in the brake system
when the brakes are applied hard (e.g. when
driving downhill). This impairs braking effi-
ciency. You should have the brake fluid renewed at
regular intervals. The brake fluid change inter-
vals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz.I nformation abou tapproved brake fluid
can be obtained at any qualified specialist
workshop or on the Internet at
http://bevo.mercedes-benz.com.
i Have the brake fluid regularly checked at
a qualified specialist workshop.
There is usually a notice in the engine com-
partment to remind you when the next
brake fluid change is due. Coolant
Important safety notes G
WARNING
Antifreeze is highly flammable. Fire, naked
flames and smoking are prohibited when han-
dling 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 Inter-
net at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
! Always use a suitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the engine coolin gsystem is not
sufficiently protected from corrosion and
overheating.
! The engine cooling system is filled with
coolant, which mus tbe renewed after 308
Service products and capacitiesTechnical data

15 years or after 250,000 kilometres at the
latest.
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant during operatio nwill be around
130 †.
The antifreeze/corrosio ninhibitor concentra-
tio nint he engine cooling system should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
around -37 †.
R not exceed 55% (antifreeze protection
down to -45 †). Otherwise, heat will not be
dissipated as effectively.
If the vehicle has lost coolant, top it up with
equal amounts of water and antifreeze/cor-
rosion inhibitor. Mercedes-Ben zrecom-
mends an antifreeze/corrosion inhibitor con-
centrate in accordance with MB Specifica-
tions for Service Products 310.1.
The coolant is checked with every mainte-
nance interval at a qualified specialist work-
shop.
i When the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures
adequate antifreeze and corrosion protec-
tion. Washer fluid
G
WARNING
Windscreen washer fluid/antifreeze is highly
flammable. Avoid spilling windscreen washer
fluid/antifreeze on hot engine components as
it can ignite and burn. Severe burns could be
the result. !
Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or
MB WinterFit .Unsuitabl ewasher fluid
could damage the plastic lenses of the
headlamps.
! Do no tuse distilled or de-ionised water in
the washer fluid reservoir. Otherwise, the
level sensor may be damaged.
! Only the washer fluids SummerFit and
WinterFit can be mixed. Otherwise, the
spraying nozzles could become blocked.
At temperatures above freezing:
X Fill the washer fluid reservoir with a mixture
of water and washer fluid, e.g. MB Sum-
merFit.
X Mix 1 part MB SummerFit to 100 parts
water.
At temperatures below freezing:
X Fill the washer fluid reservoir with a mixture
of water and washer fluid, e.g. MB Winter-
Fit. Adapt the mixing ratio to the outside
temperatures.
X Down to Ò10 †: mix 1 part MB WinterFit to
2 parts water.
X Down to Ò20 †: mix 1 part MB WinterFit to
1 part water.
X Down to Ò29 †: mix 2 parts MB WinterFit
to 1 part water.
i Add washer fluid concentrate, e.g. MB
SummerFit or MB WinterFit, to the washer
fluid all year round. Service products and capacities
309Technical data Z