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245 Technical data
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cluster displayPractical hints Car care Index Layout of poly-V-belt drive
SLK 230 Kompressor 
routing, belt I
The engine is equipped with two poly-V-belts.
1Crankshaft
2Air conditioner compressor
3Power steering pump
4Coolant pumpSLK 230 Kompressor 
routing, belt II
For dimensions of the poly-V-belts, see page 248.
5Idler pulley 
6Generator (alternator)
7Idler pulley 
8Idler pulley 
9Supercharger
P13.20-2007-26
9
6
8
7
4
1
5
32
5
32
9
6
8
4
1
7
P13.20-2008-26 
     
        
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246 Technical data
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SLK 230 Kompressor 
routing combined, belts I and II1Crankshaft
2Air conditioner compressor
3Power steering pump
4Coolant pump
5Idler pulley 
6Generator (alternator)
7Idler pulley 
8Idler pulley 
9Supercharger
9
6
8
7
4
1
5
32P13.20-2009-26 
     
        
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247 Technical data
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belt routing1Automatic belt tensioner
2Crankshaft
3Air conditioner compressor
4Generator (alternator)
5Idler pulley
6Power steering pump
7Coolant pump
For dimensions of the poly-V-belt, see page 248.
6
5
1
2
3
7
4 
     
        
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252 Fuels, coolants, lubricants etc. - capacities
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Fuels, coolants, lubricants etc. – capacities
Veh icle c omponents and t heir respec tive lub rica nts mu st ma tch . T herefore u se  only brands tested  and rec omm end ed 
by us. Please refer to the Factory Approved Service Products pamphlet, or inquire at your authorized Mercedes-Benz 
Center.
Model Capacity Fuels, coolants, lubricants etc.
Engine with oil filter SLK 230
SLK 3206.1 US qt (5.5 l)
8.5 US qt (8.0 l)Recommended engine oils
Automatic transmission 8.5 US qt (8.0 l) Automatic transmission fluid
Manual transmission SLK 230
SLK 3201.6 US qt (1.5 l)
1.9 US qt (1.8 l)Transmission oil
Rear axle 1.4 US qt (1.3 l) Hypoid gear oil SAE 90, 85 W 90
Power steering approx. 1.1 US qt (1.0 l) MB Power steering fluid
Front wheel hubs approx. 1.5 oz (43 g) each High temperature roller bearing grease
Brake system approx. 0.5 US qt (0.5 l) MB Brake f luid (DOT 4)
Cooling system SLK 230
SLK 320approx. 9.8 US qt (9.3 l)
a p p r ox .  11.8   U S   q t  ( 11.2  l )MB Anticorrosion / antifreeze 
     
        
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253 Fuels, coolants, lubricants etc. - capacities
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cluster displayPractical hints Car care Index Windshield / Headlamp 
washer systemapprox. 7.4 US qt (7.0 l) MB Windshield washer
concentrate “S” 
1
Fuel tank including
a reserve ofapprox. 15.8 US gal (60.0 l)
approx. 2.1 US gal (8.0 l)Premium unleaded gasoline:
Posted Octane 91 (Avg. of 96 RON / 86 MON)
Air conditioner system R-134a refrigerant and special PAC lubricant 
(Never R-12)1 Use MB Windshield Washer Concentrate “S” and water for temperatures above freezing or MB Windshield Washer Concentrate “S” and 
commercially available premixed windshield washer solvent / antifreeze for temperatures below freezing. Follow suggested mixing ratios, see 
page 195.
Model Capacity Fuels, coolants, lubricants etc. 
     
        
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254 Fuels, coolants, lubricants etc. - capacities
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Engine oils
Engine oils are specifically tested for their suitability in 
our engines. Therefore, use only engine oils 
recommended by Mercedes-Benz. Information on 
recommended brands is available at your authorized 
Mercedes-Benz Center.
Please follow Service Booklet recommendations for 
scheduled oil changes. Failure to do so could result in 
engine damage not covered by the Mercedes-Benz 
Limited Warranty.
Engine oil additives
Do not blend oil additives with engine oil. They may be 
harmful to the engine operation.
Damage or malfunctions resulting from blending oil 
additives are not covered by the Mercedes-Benz Limited 
War ra nt y.Air conditioner refrigerant
R-134a (H FC) ref rigerant a nd special PAG l ubricating oil 
is used in the air conditioner system.
Never use R-12 (CFC) or mineral-based lubricating oil, 
otherwise damage to the system will occur.
Brake fluid
During vehicle operation, the boiling point of the brake 
fluid is continuously reduced through the absorption of 
moisture from the atmosphere. Under extremely hard 
operating conditions, this moisture content can lead to 
the formation of bubbles in the system thus reducing 
the system‘s efficiency.
The brake fluid must therefore be replaced every two 
years, preferably in the spring.
It is recommended to use only brake fluid approved by 
Mercedes-Benz. Your authorized Mercedes-Benz Center 
will provide you with additional information. 
     
        
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255 Fuels, coolants, lubricants etc. - capacities
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Caution!
To maintain the engine’s durability and performance, 
premium unleaded gasoline must be used. If premium 
unleaded is not available and low octane fuel is used, 
follow these precautions:
•have the fuel tank filled only partially with unleaded 
regular and fill up with premium unleaded as soon 
as possible,
•avoid full throttle driving and abrupt acceleration,
•do not exceed 
2/3 of maximum accelerator pedal 
position, if the vehicle is fully loaded or operating in 
mountainous terrain.Fuel requirements
Use only Premium unleaded meeting ASTM
standard D 439:
The octane number (posted at the pump) must be 
91 min. It is an average of both the Research (R) octane 
number and the Motor (M) octane number: [(R+M) / 2]. 
This is also known as ANTI-KNOCK INDEX.
Unleaded gasoline containing oxygenates such as 
Ethanol, IPA, IBA and TBA can be used provided the 
ratio of any one of these oxygenates to gasoline does not 
exceed 10%, MTBE not to exceed 15%.
The ratio of Methanol to gasoline must not exceed 3% 
plus additional cosolvents.
Using mixtures of Ethanol and Methanol is not allowed. 
Gasohol, which contains 10% Ethanol and 90% unleaded 
gasoline, can be used.
These blends must also meet all other fuel requirements 
such as resistance to spark knock, boiling range, vapor 
pressure etc.. 
     
        
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256 Fuels, coolants, lubricants etc. - capacities
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Gasoline additives 
A major concern among engine manufacturers is carbon 
build up caused by gasoline. Mercedes-Benz 
recommends the use of only quality gasoline containing 
additives that prevent the build up of carbon deposits.
After an extended period of using fuels without such 
a d d i t i ve s , c a r b o n  d e po si t s  c a n  b u il d  u p e s pe c ia l ly  o n t h e  
intake valves and in the combustion area, leading to 
engine performance problems such as:
•warm-up hesitation,
•unstable idle,
•knocking / pinging,
•misfire,
•power loss.
Do not blend other specific fuel additives with fuel. 
They only result in unnecessary cost, and may be 
harmful to the engine operation.
Damage or malfunctions resulting from poor fuel 
quality or from blending specific fuel additives are not 
covered by the Mercedes-Benz Limited Warranty.Coolants
The engine coolant is a mixture of water and 
anticorrosion / antifreeze, which provides:
•corrosion protection,
•freeze protection,
•boiling protection (by increasing the boiling point).
The cooling system was filled at the factory with a 
coolant providing freeze protection to approximately 
-22°F (-30°C) and corrosion protection.
If the antifreeze mixture is effective to -22°F (-30°C), the 
boiling point of the coolant in the pressurized cooling 
system is reached at approximately 266°F (130°C).
The cool ant sol ution must be used  yea r round to provide 
the necessary corrosion protection and increase in the 
boil-over protection. You should have it replaced every 
3years.
To provide the important corrosion protection, the 
solution must be at least 45% anticorrosion / antifreeze 
(equals a freeze protection to approx. - 22 °F [- 30 °C]). If 
you use a solution that is more than 55% anticorrosion /
antifreeze (freeze protection to approx. - 49 °F [- 45°C]),