Prem Ium Unleaded G Asoline; Fuel Requirem Ents; G Asoline A Dditives - Mercedes-Benz C 230 1998 Owner's Manual

Prem ium U nleaded G asoline
Caution!
To m aintain the eng in e 's durability
and perform ance, prem ium un­
leaded gasoline m ust 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 prem ium un­
leaded 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 m axim um
accelerator pedal position, if the
vehicle is fully loaded or operat­
ing in m ountainous terrain.

Fuel Requirem ents

Use only Prem ium unleaded
meeting ASTM standard D 439:
The octane num ber (posted at the
pump) m ust 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 AN TI-KN O C K
INDEX.
Unleaded gasoline containing
oxygenates such as Ethanol, I PA,
I BA 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 M ethanol to gasoline
m ust not exceed 3% plus addi­
tional cosolvents.
Using m ixtures of Ethanol and
Methanol is not allowed. Gasohol,
which contains 10% Ethanol and
90% unleaded gasoline, can be
used.
These blends m ust also m eet all
other fuel requirem ents such as
resistance to spark knock, boiling
range, vapor pressure etc..

G asoline A dditives

A m ajor concern am ong engine
m anufacturers is carbon build up
caused by gasoline. Mercedes-
Benz recom m ends the use of only
quality gasoline containing
additives that prevent the build up
of carbon deposits.
A fter an extended period of using
fuels w ithout such additives,
carbon deposits can build up
especially on the intake valves and
in the com bustion area, leading to
engine perform ance problem s such
as:
• w arm -up hesitation,
• unstable idle,
• knocking/pinging,
• misfire,
• pow er loss.
Do not blend other specific fuel
additives with fuel. They only result
in unnecessary cost, and may be
harm ful to the engine operation.
Dam age or m alfunctions resulting
from poor fuel quality or from blen­
ding specific fuel additives are not
covered by the M ercedes-Benz
Lim ited W arranty.