Premium Unleaded G Asoline; Fuel Requirements; Gasoline Additives - Mercedes-Benz SLK 230 KOMPRESSOR 1999 Owner's Manual

Premium Unleaded G asoline

Caution!
To maintain the engine's durability
and perform ance, premium 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 premium un­
leaded as soon as possible,
• avoid full throttle driving and
abrupt acceleration,
• 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 Requirements

Use only Premium unleaded
m eeting 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 o f any one o f these oxy­
genates to gasoline does not
exceed 10%, MTBE not to exceed
15
% .
The ratio of M ethanol to gasoline
m ust not exceed 3% plus addition­
al cosolvents.
Using m ixtures of Ethanol and
M ethanol 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..

Gasoline Additives

A m ajor concern among engine
m anufacturers is carbon build up
caused by gasoline. Mercedes-
Benz recom m ends to use 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
harmful to the engine operation.
Dam age or m alfunctions resulting
from poor fuel quality or from
blending specific fuel additives are
not covered by the M ercedes-Benz
Limited W arranty.
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