Gasoline; Additives; Requirements; Fuel Requirements - Mercedes-Benz 2009 CL-Class Operator's Manual

with premium unleaded gasoline as soon
as possible.
Avoid full throttle driving and abrupt
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acceleration.
Do not exceed an engine speed of
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3 000 rpm if the vehicle is loaded with a
light load such as two persons and no
luggage.
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Do not exceed / of maximum
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3
accelerator pedal position if the vehicle
is fully loaded or operating in
mountainous terrain.

Fuel requirements

Only use premium unleaded gasoline. 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.
Reformulated gasolines (RFG) and/or
unleaded gasoline containing oxygenates
such as ethanol, TAME, ETBE, 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.

Gasoline additives

A major concern among engine
manufacturers is carbon build-up caused by
gasoline. Mercedes-Benz 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
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Unstable idle
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Knocking/pinging
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Technical data
Fuels, coolants, lubricants etc.
Misfire
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Power loss
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In areas where carbon deposits may be
encountered due to lack of availability of
gasoline which contains these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles.
Contact an authorized Mercedes-Benz Center
or visit www.mbusa.com (USA only) 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 cost and may
be harmful to the 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 or by any pre-owned
or Extended Limited warranties.
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