Mercedes-Benz C-CLASS WAGON C 240 - Manual (Page 434)

432
Technical data
Fuels, coolants, lubricants, etc.
Premium unleaded gasoline Fuel requirements
Only use premium unleaded fuel:
ț 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 must not 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:
ț Have the fuel tank only partially
filled with unleaded regular and fill
up with premium unleaded as soon
as possible.
ț Avoid full throttle driving and abrupt
acceleration.
ț 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.
ț Do not exceed 2 /
3
of maximum
accelerator pedal position if the
vehicle is fully loaded or operating
in mountainous terrain.
i
Flexible Fuel Vehicles (identified by a
label reading Premium gasoline or
E85 only! on fuel filler flap) are
designed to operate on premium
unleaded gasoline or ethanol fuel (E85)
or any mixture of these two.
For more information, see “Flexible
Fuel Vehicles” (
୴ page 433).