Premium Unleaded Gasoline
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 an engine speed of 3000 rpm, if the vehicle is loaded with a light load such as two
persons and no luggage,
• do not exceed 2/3 of maximum accelerator pedal positi on, if the vehicle is fully loaded or operating
in mountainous terrain.
Fuel Requirements
Use only Premium unleaded meeting ASTM standar d 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 k nown as ANTI-KNOCK INDEX. Unleaded gasoline
containing oxygenates such as Ethanol, I PA, IBA and TBA can be used provided the ratio of any
one of these oxygenates to gasoline does not exce ed 10%, MTBE not to exceed 15%. The ratio of
Methanol to gasoline must not exceed 3% plus additional components. Using mixtures of Ethanol
and Methanol is not allowed. Gasohol, which c ontains 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..
Gasoline Additives
A major concern among engine manufacturers is carbon build up caused by gasoline. Mercedes-
Benz recommends the use of only quality gasoline cont aining additives that prevent the build up of
carbon deposits. After an extended period of using fu els without such additives, carbon deposits can
build up especially on the 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 malfunct ions 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 approx. -22°F
(-30°C) and corrosion protection. The coolant solution must be used year round to provide the
necessary corrosion protection and increase in the boil-over protection. You should have it replaced
every 3 years. 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]), the engine
temperature will increase due to the lower heat transfer capability of the solution. Therefore, do not
use more than this amount of anticorrosion/antifreeze. If the coolant level is low, water and MB
anticorrosion/antifreeze should be used to bring it up to the proper level (have cooling system
checked for signs of leakage). The water in the cooling system must meet minimum requirements,
which are usually satisfied by normal drinking water. If you are not sure about the water quality,
consult your authorized Mercedes-Benz dealer.
Anticorrosion/antifreeze
Your vehicle contains a number of aluminum parts. The use of aluminum components in motor
vehicle engines necessitates that anticorrosion/antifreeze coolant used in such engines be specifically
formulated to protect the aluminum parts. (Failure to use such anticorrosion/antifreeze coolant will
result in a significantly shortened service life.)
Therefore the following product is strongly recommended for use in your car: Mercedes-Benz
Anticorrosion/Antifreeze Agent. Before the start of the winter season (or once a year in the hot
southern regions), you should have the anticorrosion/antifreeze concentration checked. The coolant is
also regularly checked each time you bring your vehicle to your authorized Mercedes-Benz dealer for
service.
Model Approx.freeze Protection
-35°F
(~37°C)
-49°F
(-45°C)
C 230 Kompressor 5.0 US qt
(4.75 I)
5.5 US qt
(5.25 I)
C 280 5.3 US qt
(5.0 I)
5.8 US qt
(5.5 I)
C 43 AMG 5.9US qt
(5.6 I)
6.6 US qt
(6.2 I)
