333 Technical data
Fuels, coolants, lubricants etc.
Premium unleaded gasoline
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 num-
ber and the Motor (M) octane number: 
(R+M) / 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.
!To maintain the engine’s durability and 
performance, premium unleaded gaso-
line must be used. If premium unleaded 
is not available and low octane fuel is 
used, follow these precautions:
Have the fuel tank only partially 
filled 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 
3 000 rpm if the vehicle is loaded 
with a light load such as two per-
sons and no luggage.
Do not exceed
2/3 of maximum 
accelerator pedal position if the 
vehicle is fully loaded or operating 
in mountainous terrain.
iFlexible Fuel Vehicles (MY 2003 
Mercedes-Benz C 320 models, except 
those equipped with manual transmis-
sion or 4 - MATIC system*) are 
designed to operate on premium 
unleaded gasoline or Ethanol fuel (E85) 
or any mixture of these two.
See notes on Flexible Fuel Vehicles 
(page 334). 
343 Technical terms
Kickdown
Depressing the accelerator past the 
point of resistance shifts the transmis-
sion down to the lowest possible gear. 
This very quickly accelerates the vehi-
cle and should not be used for normal 
acceleration needs.
Lock button
Button on the door which indicates 
whether the door is locked or un-
locked. Pushing the lock button down 
on an individual door from inside will 
lock that door.
Memory function*
Used to store three individual seat, 
steering wheel and mirror positions for 
each key.Menu
The control system displays are ar-
ranged in menus. Each menu contains 
a number of commands for particular 
systems. In the Audio menu, for exam-
ple, you will find the commands 
SELECT 
RADIO STATION
 or
 OPERATE CD PLAYER
. 
Using commands you can directly 
change the settings for your vehicle.
MON
(M
otor O
ctane N
umber)
The Motor Octane Number for gasoline 
as determined by a standardized meth-
od. It is an indication of a gasoline's 
ability to resist undesired detonation 
(knocking). The average of both the 
MON (Motor Octane Number) and 
->RON (Research Octane Number) is 
posted at the pump, also known as 
ANTI-KNOCK INDEX.Multifunction display
The display field in the instrument clus-
ter used to present information provid-
ed by the control system.
Multifunction steering wheel
Steering wheel with buttons for operat-
ing the control system.
Overspeed range
Engine speeds within the red marking 
of the tachometer dial. Avoid this en-
gine speed range, as it may result in se-
rious engine damage that is not 
covered by the Mercedes-Benz Limited 
Warranty.