300 Operation
Engine compartment
Unscrew filler cap1 from filler neck.
Add engine oil as required.
Be careful not to overfill with oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap1 back on filler neck.
For more information on engine oil, see
“Technical data” (
page 443) and
(
page 445).
Transmission fluid level*
Vehicles with automatic transmission*:
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Center
check the transmission.Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
!Excess oil must be siphoned or drained off.
It could cause damage to the engine and
emission control system not covered by the
Mercedes-Benz Limited Warranty.Warning!G
In order to avoid any potentially serious
burns:
Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature gauge indi-
cates that the coolant is overheated.
Do not remove pressure cap on coolant
reservoir if coolant temperature is
above 158°F (70°C). Allow engine to
cool down before removing cap. The
coolant reservoir contains hot fluid and
is under pressure.
447 Technical data
Fuels, coolants, lubricants, etc.
Fuel requirements
Only use premium unleaded fuel:
The octane number (posted at the
pump) must be 91 min. It is an
average of both the Research Octane
Number (RON) and the Motor Octane
Number (MON): (RON+MON)/2. This is
also known as the 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.
Gasoline additives
A major concern among engine manufac-
turers is carbon build-up caused by gaso-
line. Mercedes-Benz only recommends
only the use of quality gasoline containing
additives that prevent the build-up of
carbon deposits.
After an extended period of using fuels
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 lossIn areas where carbon deposits may be
encountered due to lack of availability of
gasolines which contain these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles. Refer to Factory
Approved Service Products pamphlet
(USA only) or contact an authorized
Mercedes-Benz Center for a listing of
approved product(s). Follow directions on
product label.
Do not blend other fuel additives with fuel.
This only results in unnecessary costs and
may be harmful to engine operation.
!Damage or malfunction resulting from poor
fuel quality or from blending additional fuel
additives other than those tested and approved
by us for use on Mercedes-Benz vehicles are not
covered by the Mercedes-Benz Limited
Warranty.
